# Online Calculators — Full Catalog

> Machine-readable index of all calculators, categories, and site metadata. Generated 2026-06-25. Canonical site: https://online-calculators.com

## Site Metadata

- name: Online Calculators
- url: https://online-calculators.com
- description: Fast, accurate, and free online calculators for finance, health, math, business, and unit conversion. EMI, SIP, BMI, GST, percentage, and 1000+ more calculators.
- operator: Nitin Kumar
- contact: onlinecalculatorsinfo@gmail.com
- github: https://github.com/nitinkanish/nitinkanish.github.io
- linkedin: https://www.linkedin.com/company/onlinecalculators/
- stack: Jekyll, GitHub Pages, vanilla JavaScript (client-side calculators), SCSS, PWA
- analytics: Google Analytics 4 (G-BJLB2TWL8B), loaded only after cookie consent

## Architecture (for contributors)

- Calculator definitions: `_data/calculators.yml`
- Dashboard copy: `_data/dashboard_pages.yml`
- SEO titles: `_data/seo.yml`
- Long-form content: `_data/calc_content.yml`
- Related links: `_data/calc_relations.yml`
- Forms: `_includes/calc-forms/{type}.html`
- Logic: `assets/js/calculators/{type}.js`
- Layout: `_layouts/calculator.html` (15-section dashboard)
- Regenerate pages: `ruby scripts/generate_pages.rb --force`
- Regenerate llms files: `ruby scripts/generate_llms_txt.rb`

## Categories

### Finance Calculators
- slug: finance
- url: https://online-calculators.com/finance/
- description: Plan your financial future with EMI, SIP, FD, compound interest, and loan calculators. Make informed investment and borrowing decisions with accurate projections.
- seo_title: Free Finance Calculators — EMI, SIP, FD & Loan Payoff Tools

### Mortgage Calculators
- slug: mortgage
- url: https://online-calculators.com/mortgage/
- description: Calculate monthly mortgage payments, affordability, and amortization schedules for home loans and property financing.
- seo_title: Free Mortgage Calculators — Payment & Affordability Tools

### Health Calculators
- slug: health
- url: https://online-calculators.com/health/
- description: Track your wellness with BMI, BMR, calorie, pregnancy, and fitness calculators. Understand your body metrics and set achievable health goals.
- seo_title: Free Health Calculators — BMI, BMR, Calorie & Pregnancy Tools

### Math & Percentage Calculators
- slug: math
- url: https://online-calculators.com/math/
- description: Solve everyday math problems with fraction, ratio, percentage, exponent, square root, and rounding calculators. Quick, accurate results for students and professionals.
- seo_title: Free Math Calculators — Fraction, Ratio, Percentage, Square Root & More

### Unit Converters
- slug: converters
- url: https://online-calculators.com/converters/
- description: Convert length, weight, temperature, and more between metric and imperial units instantly with precision.
- seo_title: Free Unit Converters — Length, Weight, Temperature & Speed

### Business Calculators
- slug: business
- url: https://online-calculators.com/business/
- description: Calculate profit margins, GST, markup, and business metrics to optimize pricing and tax compliance for your enterprise.
- seo_title: Free Business Calculators — GST, Margin & Markup Tools

### Construction Calculators
- slug: construction
- url: https://online-calculators.com/construction/
- description: Estimate materials, areas, volumes, and costs for construction and renovation projects.
- seo_title: Free Construction Calculators — Area & Volume Tools

### Education Calculators
- slug: education
- url: https://online-calculators.com/education/
- description: GPA, grade, and academic calculators for students and educators.
- seo_title: Free Education Calculators — GPA & Weighted Grade Tools

### Statistics Calculators
- slug: statistics
- url: https://online-calculators.com/statistics/
- description: Mean, median, standard deviation, and statistical analysis tools for data professionals.
- seo_title: Free Statistics Calculators — Mean, Median & Standard Deviation

### Scientific Calculators
- slug: scientific
- url: https://online-calculators.com/scientific/
- description: Advanced scientific and engineering calculators for complex mathematical operations.
- seo_title: Free Scientific Calculators — Advanced Math & Engineering Tools

### Date & Time Calculators
- slug: date-time
- url: https://online-calculators.com/date-time/
- description: Calculate age, date differences, and time intervals with precision.
- seo_title: Free Date Calculators — Age, Days Between Dates & Time Tools

### Fitness Calculators
- slug: fitness
- url: https://online-calculators.com/fitness/
- description: Track macros, heart rate zones, and workout metrics for optimal fitness performance.
- seo_title: Free Fitness Calculators — Macro & Heart Rate Zone Tools

## Calculators

### EMI Calculator
- slug: emi-calculator
- url: https://online-calculators.com/finance/emi-calculator/
- category: finance
- calculator_type: emi
- description: Calculate monthly EMI for home, car, and personal loans with amortization breakdown.
- formula: EMI = P × r × (1+r)^n / ((1+r)^n - 1)
- keywords: emi calculator, loan emi calculator, home loan emi
- seo_title: Free EMI Calculator for Home & Car Loans
- featured: true
- popular: true

### SIP Calculator
- slug: sip-calculator
- url: https://online-calculators.com/finance/sip-calculator/
- category: finance
- calculator_type: sip
- description: Estimate mutual fund SIP returns with step-up options and wealth projection charts.
- formula: FV = P × ((1+r)^n - 1) / r × (1+r)
- keywords: sip calculator, mutual fund sip calculator, sip return calculator
- seo_title: Free SIP Calculator — Mutual Fund Returns & Wealth Projection
- featured: true
- popular: true

### FD Calculator
- slug: fd-calculator
- url: https://online-calculators.com/finance/fd-calculator/
- category: finance
- calculator_type: fd
- description: Calculate fixed deposit maturity amount with quarterly, monthly, and annual compounding.
- formula: A = P × (1 + r/n)^(n×t)
- keywords: fd calculator, fixed deposit calculator, fd interest calculator
- seo_title: Free FD Calculator — Fixed Deposit Maturity & Interest
- featured: false
- popular: true

### Compound Interest Calculator
- slug: compound-interest-calculator
- url: https://online-calculators.com/finance/compound-interest-calculator/
- category: finance
- calculator_type: compound-interest
- description: Calculate compound interest with regular contributions and visualize wealth growth over time.
- formula: A = P(1 + r/n)^(nt) + PMT × [((1 + r/n)^(nt) - 1) / (r/n)]
- keywords: compound interest calculator, interest calculator, compounding calculator
- seo_title: Free Compound Interest Calculator with Monthly Contributions
- featured: true
- popular: true

### BMI Calculator
- slug: bmi-calculator
- url: https://online-calculators.com/health/bmi-calculator/
- category: health
- calculator_type: bmi
- description: Calculate Body Mass Index and get personalized health category recommendations.
- formula: BMI = weight (kg) / height (m)²
- keywords: bmi calculator, body mass index calculator, bmi chart
- seo_title: Free BMI Calculator — Body Mass Index & Health Category
- featured: true
- popular: true

### BMR Calculator
- slug: bmr-calculator
- url: https://online-calculators.com/health/bmr-calculator/
- category: health
- calculator_type: bmr
- description: Calculate Basal Metabolic Rate to understand daily calorie needs at rest.
- formula: BMR (M) = 10W + 6.25H - 5A + 5; BMR (F) = 10W + 6.25H - 5A - 161
- keywords: bmr calculator, basal metabolic rate calculator, metabolism calculator
- seo_title: Free BMR Calculator — Basal Metabolic Rate & TDEE
- popular: true

### Calorie Calculator
- slug: calorie-calculator
- url: https://online-calculators.com/health/calorie-calculator/
- category: health
- calculator_type: calorie
- description: Calculate daily calorie needs for weight loss, maintenance, or muscle gain goals.
- formula: TDEE = BMR × Activity Factor
- keywords: calorie calculator, daily calorie calculator, tdee calculator
- seo_title: Free Daily Calorie Calculator for Weight Loss & Gain
- featured: false
- popular: true

### Percentage Calculator
- slug: percentage-calculator
- url: https://online-calculators.com/math/percentage-calculator/
- category: math
- calculator_type: percentage
- description: Free percentage calculator for X% of Y, percent change, increase, decrease, and reverse percentage — with formula shown instantly.
- formula: Percentage = (Part / Whole) × 100
- keywords: percentage calculator, percent calculator, percentage increase calculator, percentage change calculator, reverse percentage calculator, what percent calculator
- seo_title: Free Percentage Calculator — Increase, Decrease, Change & Reverse %
- meta_description: Calculate percentages instantly — X% of Y, percent change, increase, decrease, and reverse percentage. Free online tool with formulas shown.
- featured: true
- popular: true

### Fraction Calculator
- slug: fraction-calculator
- url: https://online-calculators.com/math/fraction-calculator/
- category: math
- calculator_type: fraction
- description: Free fraction calculator to add, subtract, multiply, and divide fractions — auto-simplifies to lowest terms with decimal result.
- formula: a/b ± c/d with common denominator; result simplified via GCD
- keywords: fraction calculator, add fractions calculator, simplify fraction calculator, fraction to decimal, multiply fractions calculator, divide fractions calculator
- seo_title: Free Fraction Calculator — Add, Subtract, Multiply, Divide & Simplify
- meta_description: Add, subtract, multiply, and divide fractions online. Auto-simplifies to lowest terms and shows decimal equivalent. Free fraction calculator.
- featured: true
- popular: true

### Ratio Calculator
- slug: ratio-calculator
- url: https://online-calculators.com/math/ratio-calculator/
- category: math
- calculator_type: ratio
- description: Free ratio calculator to simplify ratios and solve proportions — find missing values with cross-multiplication instantly.
- formula: a:b simplified by GCD; scale via cross-multiplication
- keywords: ratio calculator, simplify ratio calculator, proportion calculator, scale ratio calculator, ratio simplifier, cross multiplication calculator
- seo_title: Free Ratio Calculator — Simplify Ratios & Solve Proportions
- meta_description: Simplify ratios to lowest terms and find missing values in proportions using cross-multiplication. Free ratio and proportion calculator.
- popular: true

### Square Root Calculator
- slug: square-root-calculator
- url: https://online-calculators.com/math/square-root-calculator/
- category: math
- calculator_type: square-root
- description: Free square root calculator — find √n for any number, detect perfect squares, and see exact or decimal results.
- formula: √n = n^0.5
- keywords: square root calculator, sqrt calculator, perfect square calculator, root calculator, square root of
- seo_title: Free Square Root Calculator — √n, Perfect Squares & Decimals
- meta_description: Calculate square roots of any non-negative number. Detects perfect squares and shows exact or decimal results. Free √ calculator online.

### Exponent Calculator
- slug: exponent-calculator
- url: https://online-calculators.com/math/exponent-calculator/
- category: math
- calculator_type: exponent
- description: Free exponent calculator — compute base raised to any power including negative and decimal exponents instantly.
- formula: result = base^exponent
- keywords: exponent calculator, power calculator, raise to power calculator, index calculator, negative exponent calculator
- seo_title: Free Exponent Calculator — Power, Index & Negative Exponents
- meta_description: Calculate base raised to any exponent — positive, negative, or decimal. Free online power calculator with instant results.
- popular: true

### Rounding Calculator
- slug: rounding-calculator
- url: https://online-calculators.com/math/rounding-calculator/
- category: math
- calculator_type: rounding
- description: Free rounding calculator — round, floor, ceil, or truncate any number to 0–10 decimal places instantly.
- formula: Round(n, d) = round n to d decimal places
- keywords: rounding calculator, round to decimal places, round number calculator, decimal rounding tool, floor calculator, ceil calculator
- seo_title: Free Rounding Calculator — Round, Floor, Ceil & Truncate Decimals
- meta_description: Round numbers to any decimal place. Choose round, floor, ceil, or truncate mode. Free decimal rounding tool for math and finance.

### Age Calculator
- slug: age-calculator
- url: https://online-calculators.com/date-time/age-calculator/
- category: date-time
- calculator_type: age
- description: Calculate exact age in years, months, days, hours, and minutes from date of birth.
- formula: Age = Current Date - Date of Birth
- keywords: age calculator, date of birth calculator, how old am i
- seo_title: Free Age Calculator — Exact Age in Years, Months & Days
- popular: true

### Scientific Calculator
- slug: scientific-calculator
- url: https://online-calculators.com/scientific/scientific-calculator/
- category: scientific
- calculator_type: scientific
- description: Full-featured scientific calculator with trigonometry, logarithms, and advanced functions.
- formula: Varies by operation
- keywords: scientific calculator, online scientific calculator, math calculator
- seo_title: Free Online Scientific Calculator with Trigonometry
- featured: true
- popular: true

### Length Converter
- slug: length-converter
- url: https://online-calculators.com/converters/length-converter/
- category: converters
- calculator_type: length-converter
- description: Convert between meters, feet, inches, miles, kilometers, and more length units.
- formula: Target = Source × Conversion Factor
- keywords: length converter, feet to meters, inch to cm converter
- seo_title: Free Length Converter — Feet to Meters, Inches to CM
- featured: false
- popular: true

### Weight Converter
- slug: weight-converter
- url: https://online-calculators.com/converters/weight-converter/
- category: converters
- calculator_type: weight-converter
- description: Convert between kilograms, pounds, ounces, grams, stones, and more weight units.
- formula: Target = Source × Conversion Factor
- keywords: weight converter, kg to lbs, pounds to kg converter
- seo_title: Free Weight Converter — KG to LBS & Pounds to Kilograms
- popular: true

### Temperature Converter
- slug: temperature-converter
- url: https://online-calculators.com/converters/temperature-converter/
- category: converters
- calculator_type: temperature-converter
- description: Convert between Celsius, Fahrenheit, and Kelvin temperature scales instantly.
- formula: °F = (°C × 9/5) + 32; K = °C + 273.15
- keywords: temperature converter, celsius to fahrenheit, fahrenheit to celsius
- seo_title: Free Temperature Converter — Celsius to Fahrenheit & Kelvin
- featured: false
- popular: true

### Profit Margin Calculator
- slug: profit-margin-calculator
- url: https://online-calculators.com/business/profit-margin-calculator/
- category: business
- calculator_type: profit-margin
- description: Calculate gross, operating, and net profit margins for your business pricing strategy.
- formula: Profit Margin = (Revenue - Cost) / Revenue × 100
- keywords: profit margin calculator, margin calculator, markup calculator
- seo_title: Free Profit Margin Calculator — Markup & Revenue Analysis
- popular: true

### GST Calculator
- slug: gst-calculator
- url: https://online-calculators.com/business/gst-calculator/
- category: business
- calculator_type: gst
- description: Calculate GST inclusive and exclusive amounts for Indian tax rates of 5%, 12%, 18%, and 28%.
- formula: GST Amount = Price × Rate / 100; Inclusive Price = Price × (1 + Rate/100)
- keywords: gst calculator, gst inclusive calculator, india gst calculator
- seo_title: Free GST Calculator India — 5%, 12%, 18% & 28% Tax
- featured: true
- popular: true

### Pregnancy Due Date Calculator
- slug: pregnancy-calculator
- url: https://online-calculators.com/health/pregnancy-calculator/
- category: health
- calculator_type: pregnancy
- description: Calculate your due date, pregnancy week, trimester, and days until delivery from LMP or conception date.
- formula: Due Date = LMP + 280 days (Naegele's Rule)
- keywords: pregnancy calculator, due date calculator, pregnancy week calculator, gestational age calculator
- seo_title: Free Pregnancy Calculator — Due Date & Gestational Age
- featured: true
- popular: true

### Mortgage Calculator
- slug: mortgage-calculator
- url: https://online-calculators.com/mortgage/mortgage-calculator/
- category: mortgage
- calculator_type: mortgage
- description: Calculate monthly mortgage payments, total interest, and amortization for US home loans.
- formula: M = P × r × (1+r)^n / ((1+r)^n - 1)
- keywords: mortgage calculator, home loan calculator, monthly mortgage payment, mortgage payment calculator
- seo_title: Free Mortgage Calculator — Monthly Home Loan Payment
- featured: true
- popular: true

### Date Difference Calculator
- slug: date-difference-calculator
- url: https://online-calculators.com/date-time/date-difference-calculator/
- category: date-time
- calculator_type: date-difference
- description: Calculate exact days, weeks, months, and years between any two dates instantly.
- formula: Difference = End Date − Start Date
- keywords: date difference calculator, days between dates, date calculator, time between dates
- seo_title: Free Date Difference Calculator — Days Between Two Dates
- featured: true
- popular: true

### Macro Calculator
- slug: macro-calculator
- url: https://online-calculators.com/fitness/macro-calculator/
- category: fitness
- calculator_type: macro
- description: Calculate daily protein, carbs, and fat targets based on your calories and fitness goals.
- formula: Protein g × 4 + Carbs g × 4 + Fat g × 9 = Calories
- keywords: macro calculator, macronutrient calculator, protein calculator, iifym calculator
- seo_title: Free Macro Calculator — Protein, Carbs & Fat Targets
- featured: true
- popular: true

### GPA Calculator
- slug: gpa-calculator
- url: https://online-calculators.com/education/gpa-calculator/
- category: education
- calculator_type: gpa
- description: Calculate weighted GPA on a 4.0 scale from course grades and credit hours.
- formula: GPA = Σ(Grade Points × Credits) / Σ(Credits)
- keywords: gpa calculator, grade point average calculator, college gpa calculator, weighted gpa calculator
- seo_title: Free GPA Calculator — Weighted 4.0 Scale Grade Point Average
- featured: true
- popular: true

### Area Calculator
- slug: area-calculator
- url: https://online-calculators.com/construction/area-calculator/
- category: construction
- calculator_type: area
- description: Calculate area of rectangle, circle, triangle, and room layouts for construction and renovation.
- formula: Rectangle: l×w | Circle: πr² | Triangle: ½bh
- keywords: area calculator, square footage calculator, room area calculator, construction area calculator
- seo_title: Free Area Calculator — Square Footage & Room Dimensions
- featured: true
- popular: true

### Standard Deviation Calculator
- slug: standard-deviation-calculator
- url: https://online-calculators.com/statistics/standard-deviation-calculator/
- category: statistics
- calculator_type: standard-deviation
- description: Calculate mean, variance, and standard deviation for any dataset — sample or population.
- formula: σ = √(Σ(x−μ)² / N)
- keywords: standard deviation calculator, statistics calculator, variance calculator, mean calculator
- seo_title: Free Standard Deviation Calculator — Mean & Variance
- featured: true
- popular: true

### Loan Payoff Calculator
- slug: loan-payoff-calculator
- url: https://online-calculators.com/finance/loan-payoff-calculator/
- category: finance
- calculator_type: loan-payoff
- description: Calculate how extra EMI payments reduce loan tenure and total interest on home, car, and personal loans.
- formula: Interest saved = Original total interest − New total with extra payments
- keywords: loan payoff calculator, extra emi calculator, loan prepayment calculator, interest savings calculator
- seo_title: Free Loan Payoff Calculator — Extra EMI Interest Savings
- featured: true
- popular: true

### Mortgage Affordability Calculator
- slug: mortgage-affordability-calculator
- url: https://online-calculators.com/mortgage/mortgage-affordability-calculator/
- category: mortgage
- calculator_type: mortgage-affordability
- description: Calculate how much house you can afford based on income, debts, down payment, and mortgage rate.
- formula: Max payment ≈ 28% of gross monthly income (housing ratio)
- keywords: mortgage affordability calculator, how much house can I afford, home affordability calculator, mortgage qualification calculator
- seo_title: Free Mortgage Affordability Calculator — How Much House Can I Afford
- featured: true
- popular: true

### Volume Calculator
- slug: volume-calculator
- url: https://online-calculators.com/construction/volume-calculator/
- category: construction
- calculator_type: volume
- description: Calculate volume of rectangular prisms, cylinders, and spheres for concrete, fill, and tank capacity.
- formula: Box: l×w×h | Cylinder: πr²h | Sphere: ⁴⁄₃πr³
- keywords: volume calculator, cubic feet calculator, concrete volume calculator, cylinder volume calculator
- seo_title: Free Volume Calculator — Cubic Feet, Yards & Concrete
- featured: true
- popular: true

### Grade Calculator
- slug: grade-calculator
- url: https://online-calculators.com/education/grade-calculator/
- category: education
- calculator_type: grade
- description: Calculate weighted course grade from assignments, exams, and project scores with custom weights.
- formula: Grade = Σ(Score × Weight) / Σ(Weight)
- keywords: grade calculator, weighted grade calculator, final grade calculator, course grade calculator
- seo_title: Free Grade Calculator — Weighted Course Grade & Letter
- featured: true
- popular: true

### Mean Median Mode Calculator
- slug: mean-median-mode-calculator
- url: https://online-calculators.com/statistics/mean-median-mode-calculator/
- category: statistics
- calculator_type: mean-median-mode
- description: Calculate mean, median, mode, range, and count for any dataset instantly.
- formula: Mean = Σx/n | Median = middle value | Mode = most frequent
- keywords: mean median mode calculator, average calculator, statistics calculator, central tendency calculator
- seo_title: Free Mean Median Mode Calculator — Statistics Tool
- featured: true
- popular: true

### Heart Rate Zone Calculator
- slug: heart-rate-zone-calculator
- url: https://online-calculators.com/fitness/heart-rate-zone-calculator/
- category: fitness
- calculator_type: heart-rate
- description: Calculate max heart rate and training zones for fat burn, cardio, and peak performance.
- formula: Max HR ≈ 220 − Age | Zones = % of max HR
- keywords: heart rate zone calculator, max heart rate calculator, cardio zone calculator, training zones calculator
- seo_title: Free Heart Rate Zone Calculator — Max HR & Training Zones
- featured: true
- popular: true

### Speed Converter
- slug: speed-converter
- url: https://online-calculators.com/converters/speed-converter/
- category: converters
- calculator_type: speed-converter
- description: Convert speed between km/h, mph, m/s, knots, and feet per second instantly.
- formula: Target = Source × conversion factor
- keywords: speed converter, kmh to mph, mph to kmh, knots converter
- seo_title: Free Speed Converter — KM/H to MPH, Knots & M/S
- featured: true
- popular: true

### Markup Calculator
- slug: markup-calculator
- url: https://online-calculators.com/business/markup-calculator/
- category: business
- calculator_type: markup
- description: Calculate selling price, profit, and margin from cost price and markup percentage.
- formula: Selling Price = Cost × (1 + Markup%/100)
- keywords: markup calculator, markup percentage calculator, selling price calculator, cost plus pricing calculator
- seo_title: Free Markup Calculator — Selling Price from Cost
- featured: true
- popular: true

## Disclaimers

- Health calculators (BMI, BMR, calorie, pregnancy) provide estimates only — not medical advice.
- Finance calculators (EMI, SIP, FD, mortgage) are projections — verify with your bank or advisor.
- GST calculator targets Indian tax slabs; mortgage calculator uses US-style amortization.
- No personal data is stored server-side; calculations run in the user browser.