# Calculatodo

> Free online calculators for health, finance, math, geometry, calendar, other tools, and statistics. Most calculations run client-side with instant results, while some pages use server-prepared regional or dynamic data. Available in 35 languages.

Calculatodo.com provides free, ad-supported online calculators. Each calculator includes an interactive tool and educational content explaining the formulas, methodology, and practical applications. No registration required.

## Calculator Categories

- [Health Calculators](https://calculatodo.com/en/health-calculators)
- [Finance Calculators](https://calculatodo.com/en/financial-calculators)
- [Math Calculators](https://calculatodo.com/en/math-calculators)
- [Geometry Calculators](https://calculatodo.com/en/geometry-calculators)
- [Calendar Calculators](https://calculatodo.com/en/calendar-calculators)
- [Other Calculators](https://calculatodo.com/en/other-calculators)
- [Statistics Calculators](https://calculatodo.com/en/statistics-calculators)

## Health Calculators

- [BMI Calculator](https://calculatodo.com/en/calculate-body-mass-index-bmi): Calculate Body Mass Index from height and weight. Includes BMI classification and related health information.
- [Body Fat Calculator](https://calculatodo.com/en/calculate-body-fat): Estimate body fat percentage using neck, waist, and hip measurements.
- [Basal Metabolic Rate Calculator](https://calculatodo.com/en/calculate-basal-metabolic-rate-bmr): Calculate BMR using the Mifflin-St Jeor equation to estimate daily calorie needs at rest.
- [PaFi Ratio Calculator](https://calculatodo.com/en/pf-ratio-calculator): Calculate the PaO2/FiO2 ratio used to assess oxygenation and classify respiratory distress.
- [Mean Arterial Pressure (MAP) Calculator](https://calculatodo.com/en/mean-arterial-pressure-map-calculator): Estimate mean arterial pressure and pulse pressure from systolic and diastolic blood pressure.
- [Glomerular Filtration Rate (eGFR) Calculator](https://calculatodo.com/en/glomerular-filtration-rate-egfr-calculator): Estimate eGFR using the race-free CKD-EPI 2021 creatinine equation, serum creatinine, age, and sex, with KDIGO G1–G5 reference categories.
- [Ovulation and Fertile Days Calculator](https://calculatodo.com/en/ovulation-fertile-days-calculator): Estimate ovulation dates and fertile days from cycle information.

## Finance Calculators

- [Compound Interest Calculator](https://calculatodo.com/en/compound-interest-calculator): Calculate compound interest with customizable principal, rate, time period, and compounding frequency.
- [VAT Calculator](https://calculatodo.com/en/vat-calculator): Calculate Value Added Tax using country-specific rates and precision settings.
- [Simple Interest Calculator](https://calculatodo.com/en/simple-interest-calculator): Calculate simple interest from principal, annual rate, and time period.
- [NPV and IRR Calculator](https://calculatodo.com/en/net-present-value-npv-and-irr-calculator): Calculate Net Present Value (NPV) and Internal Rate of Return (IRR) for investment cash flows.
- [WACC Calculator](https://calculatodo.com/en/wacc-calculator): Calculate the Weighted Average Cost of Capital from debt, equity, tax rate, and financing costs.
- [Mortgage Calculator](https://calculatodo.com/en/mortgage-calculator): Estimate mortgage payments, interest, and repayment totals from loan terms and rates.

## Math Calculators

- [Weighted Average Calculator](https://calculatodo.com/en/weighted-average-calculator): Calculate weighted averages and weighted grades from values and weights.
- [Percentage Calculator](https://calculatodo.com/en/calculate-percentage): Calculate a percentage of a value, the percentage relationship between values, and percentage change.
- [Rule of Three Calculator](https://calculatodo.com/en/proportion-calculator): Solve direct and inverse proportions using the rule of three.
- [Binary Number Calculator](https://calculatodo.com/en/binary-number-calculator): Convert between binary and decimal and perform arithmetic with binary numbers.
- [Hexadecimal Number Calculator](https://calculatodo.com/en/hexadecimal-number-calculator): Convert between hexadecimal and decimal and perform arithmetic with hexadecimal numbers.
- [LCM Calculator](https://calculatodo.com/en/calculate-least-common-multiple-lcm): Calculate the Least Common Multiple (LCM) of two or more numbers.
- [Fraction Calculator](https://calculatodo.com/en/fraction-calculator): Add, subtract, multiply, and divide fractions, with automatic simplification.

## Geometry Calculators

- [Circle Area Calculator](https://calculatodo.com/en/calculate-area/circle): Calculate the area and circumference of a circle from its radius.
- [Square Area Calculator](https://calculatodo.com/en/calculate-area/square): Calculate the area and perimeter of a square from its side length.
- [Rectangle Area Calculator](https://calculatodo.com/en/calculate-area/rectangle): Calculate the area and perimeter of a rectangle from its width and height.
- [Cylinder Surface Area Calculator](https://calculatodo.com/en/calculate-area/cylinder): Calculate the surface area and volume of a cylinder from its radius and height.
- [Cube Surface Area Calculator](https://calculatodo.com/en/calculate-area/cube): Calculate the surface area and volume of a cube from its edge length.
- [Sphere Surface Area Calculator](https://calculatodo.com/en/calculate-area/sphere): Calculate the surface area and volume of a sphere from its radius.

## Calendar and Time Calculators

- [Age Calculator](https://calculatodo.com/en/chronological-age-calculator): Calculate exact chronological age in years, months, and days from a birth date.
- [Days Between Dates Calculator](https://calculatodo.com/en/count-days-between-dates): Count the exact number of days between two dates.
- [Add or Subtract Days to a Date](https://calculatodo.com/en/add-subtract-days-to-date): Add or subtract days, weeks, or months from a date.
- [Hours and Minutes Calculator](https://calculatodo.com/en/hours-and-minutes-calculator): Add and subtract hours and minutes for time tracking and scheduling.
- [Worked Hours and Overtime Calculator](https://calculatodo.com/en/worked-hours-and-overtime-calculator): Calculate worked hours and overtime from work schedules and hourly information.

## Other Calculators

- [Gasoline Expense Trip Calculator](https://calculatodo.com/en/calculate-gasoline-expense-trip): Estimate fuel cost for a trip from distance, fuel efficiency, and fuel price.
- [Word and Character Counter](https://calculatodo.com/en/word-character-counter): Count words, characters, sentences, and paragraphs in text.
- [Roman Numeral Converter](https://calculatodo.com/en/roman-numerals-decimal-arabic-converter): Convert between Roman numerals and decimal numbers.
- [Click Counter](https://calculatodo.com/en/click-counter): Count clicks with customizable increments, add and subtract controls, optional sound, and reset.
- [CPS Test: Clicks Per Second](https://calculatodo.com/en/cps-test-clicks-per-second): Measure clicking speed in clicks per second over 5, 10, 15, 30, or 60 seconds. Shows total clicks, CPS, and the latest 10 test results.
- [Grade Scale Generator](https://calculatodo.com/en/generate-grade-scale-score-table): Generate a grade scale table from a maximum score, passing requirement, grades, and score increments.

## Statistics Calculators

- [Mean, Median, and Mode Calculator](https://calculatodo.com/en/calculate-mean-median-mode-statistics): Calculate the mean, median, and mode of a dataset.
- [Variance Calculator](https://calculatodo.com/en/calculate-variance): Calculate population and sample variance from a set of numbers.
- [Standard Deviation Calculator](https://calculatodo.com/en/calculate-standard-deviation): Calculate population and sample standard deviation from a dataset.

## Spanish-Only Calculators

- [Boleta de Honorarios Calculator](https://calculatodo.com/calcular-boleta-de-honorarios): Calculate Chilean freelancer invoice withholding tax using the current UF value and retention rate. Spanish only.
- [Legal Holiday Calculator](https://calculatodo.com/calcular-dias-vacaciones-feriado-legal): Calculate Chilean legal vacation days based on years of service. Spanish only.

## Supported Languages

Available in 35 languages: Spanish (default), Arabic, Bulgarian, Bengali, Catalan, Czech, Danish, German, Greek, English, Estonian, Finnish, French, Hebrew, Hindi, Croatian, Hungarian, Indonesian, Italian, Japanese, Korean, Norwegian Bokmål, Dutch, Polish, Portuguese, Romanian, Russian, Serbian, Swedish, Thai, Turkish, Ukrainian, Urdu, Vietnamese, and Chinese.

Each language has localized URLs, content, and interface. Non-Spanish URLs use an explicit locale prefix, such as `/en/`; Spanish is the default locale without a prefix.

## Optional

- [Privacy Policy (EN)](https://calculatodo.com/en/privacy-policy)
- [Sitemap](https://calculatodo.com/sitemap.xml)