All calculators
Every tool, grouped by category. Jump to a section or open a calculator directly.
🏠 Real Estate
View category →Yield, cap rate and short-term rental revenue tools.
Rental Yield
Work out the gross and net rental yield on a property from its price, rent and running costs.
Open calculator →Cap Rate
Calculate the capitalization rate of an investment property from its net operating income and value.
Open calculator →Airbnb Revenue
Estimate the short-term rental revenue of your property by entering nightly rates from comparable Airbnb listings. No signup, instant report.
Open calculator →STR Bookkeeping
Upload a bank statement or Airbnb/Vrbo CSV export and get an instant short-term rental profit & loss — income, platform fees and expenses categorised automatically. No signup.
Open calculator →❤️ Health
View category →BMI, calories and body metrics.
BMI
Calculate your Body Mass Index (BMI) from your height and weight, in metric or imperial units.
Open calculator →Calorie
Estimate your daily calorie needs (TDEE) and targets for losing or gaining weight, using the Mifflin-St Jeor equation.
Open calculator →Body Fat
Estimate your body fat percentage using the US Navy tape method, from a few simple body measurements.
Open calculator →Ideal Weight
Estimate a healthy target weight for your height using the Robinson, Miller, Devine and Hamwi formulas, plus the healthy BMI range.
Open calculator →Pace
Work out your running pace per kilometre and per mile from a distance and a time, plus your average speed.
Open calculator →Water Intake
Estimate how much water to drink each day based on your body weight and how much exercise you do.
Open calculator →Macros
Split a daily calorie target into grams of protein, carbohydrate and fat using a chosen macro ratio.
Open calculator →Sleep
Find the best times to go to sleep or wake up, based on 90-minute sleep cycles.
Open calculator →Due Date
Estimate a pregnancy due date from the first day of the last menstrual period, with current progress and trimester.
Open calculator →Waist-to-Hip
Calculate your waist-to-hip ratio (WHR) and see the associated health-risk category, based on WHO thresholds.
Open calculator →Target Heart Rate
Find your maximum heart rate and target training zones for moderate and vigorous exercise, with an optional resting-heart-rate (Karvonen) adjustment.
Open calculator →📅 Date & Time
View category →Ages, date differences and countdowns.
Age
Calculate your exact age in years, months, days — plus live hours, minutes and seconds — from your date and time of birth.
Open calculator →Date Difference
Find the number of days, weeks, months and years between two dates.
Open calculator →Time Duration
Work out the hours and minutes between a start and end time — handy for timesheets and shifts. Handles overnight times and unpaid breaks.
Open calculator →Add/Subtract Date
Add or subtract days, weeks, months or years from a date to find the resulting date and day of the week.
Open calculator →Working Days
Count the number of working days (Monday to Friday) between two dates, excluding weekends.
Open calculator →Day of the Week
Find out which day of the week any date falls on — past or future — plus the day and week number of the year.
Open calculator →Countdown
Count down to any future date and time — see the days, hours, minutes and seconds remaining, updating live.
Open calculator →Add Working Days
Add or subtract a number of working days (Monday to Friday) from a date, skipping weekends — useful for delivery and deadline dates.
Open calculator →➗ Math
View category →Percentages, ratios and quick calculations.
Percentage
Work out what X% of a number is, what one number is as a percentage of another, and percentage change.
Open calculator →Ratio
Simplify a ratio to its lowest terms, see it as a decimal and percentage split, and scale it up or down.
Open calculator →Discount
Work out the sale price and how much you save from an original price and a percentage discount.
Open calculator →Tip
Calculate the tip and total on a bill, and split it evenly between any number of people.
Open calculator →Average
Find the mean, median, mode and range of a list of numbers, plus the count, sum, minimum and maximum.
Open calculator →Fraction
Add, subtract, multiply and divide two fractions, with the answer simplified and shown as a decimal and mixed number.
Open calculator →GCF & LCM
Find the greatest common factor (GCF) and least common multiple (LCM) of two or more whole numbers.
Open calculator →Exponent
Raise a number to a power. Supports negative, decimal and fractional exponents, with the result in plain and scientific notation.
Open calculator →Percentage Change
Calculate the percentage increase or decrease from one value to another, plus the absolute change.
Open calculator →Aspect Ratio
Simplify a width and height to an aspect ratio, and scale dimensions while keeping the same ratio.
Open calculator →Roman Numerals
Convert numbers to Roman numerals and Roman numerals back to numbers, from 1 to 3,999.
Open calculator →GPA
Calculate your grade point average (GPA) on the 4.0 scale from a list of letter grades.
Open calculator →Square Root
Find the square root and cube root of a number, along with its square and cube.
Open calculator →Circle
Calculate a circle's area, circumference, diameter and radius from any one of them.
Open calculator →Right Triangle
From the two shorter sides of a right-angled triangle, find the hypotenuse, area, perimeter and angles.
Open calculator →Number to Words
Convert a number into words — useful for writing cheques, contracts and invoices.
Open calculator →Standard Deviation
Find the standard deviation, variance and mean of a data set, for either a sample or a whole population.
Open calculator →Prime Factors
Break a whole number down into its prime factors, and check whether a number is prime.
Open calculator →Logarithm
Calculate the logarithm of a number to any base, plus the natural log (ln), log base 10 and log base 2.
Open calculator →Quadratic
Solve any quadratic equation ax² + bx + c = 0 using the quadratic formula, with real or complex roots, discriminant and vertex.
Open calculator →🔁 Conversion
View category →Units, measurements and everyday conversions.
Length
Convert between metres, feet, inches, miles, kilometres and more — instantly, in both metric and imperial.
Open calculator →Temperature
Convert temperatures between Celsius, Fahrenheit and Kelvin instantly.
Open calculator →Speed
Convert speed between mph, km/h, metres per second, feet per second and knots instantly.
Open calculator →Weight
Convert weight and mass between kilograms, grams, pounds, ounces, stone and tonnes.
Open calculator →Area
Convert area between square metres, square feet, acres, hectares, square kilometres and more.
Open calculator →Volume
Convert volume between litres, millilitres, US and imperial gallons, cups, pints and fluid ounces.
Open calculator →Data Storage
Convert digital storage between bits, bytes, kilobytes, megabytes, gigabytes, terabytes and their binary (KiB, MiB, GiB) equivalents.
Open calculator →Time Units
Convert time between seconds, minutes, hours, days, weeks, months and years.
Open calculator →Fuel Economy
Convert fuel economy between miles per gallon (US and imperial), litres per 100 km and kilometres per litre.
Open calculator →Height
Convert height between centimetres and feet & inches, both ways, with metres and total inches too.
Open calculator →Cooking
Convert cooking volumes between teaspoons, tablespoons, cups, fluid ounces, millilitres and litres.
Open calculator →Angle
Convert angles between degrees, radians, gradians, arcminutes, arcseconds and full turns.
Open calculator →Energy
Convert energy between joules, kilojoules, calories, kilocalories, watt-hours, kilowatt-hours and BTU.
Open calculator →Pressure
Convert pressure between pascals, kilopascals, bar, psi, atmospheres and mmHg.
Open calculator →Number Base
Convert numbers between binary, octal, decimal and hexadecimal. Enter a value in any base and see it in all four.
Open calculator →Power
Convert power between watts, kilowatts, megawatts, horsepower, metric horsepower and BTU per hour.
Open calculator →Force
Convert force between newtons, kilonewtons, dynes, pounds-force, kilograms-force and ounces-force.
Open calculator →🕌 Islamic
View category →Zakat and Hijri (Islamic calendar) tools.
Zakat
Estimate your annual Zakat at 2.5% of your net zakatable wealth — cash, gold, silver, business assets and investments, less debts.
Open calculator →Hijri Date
Convert a Gregorian (Western) date to the Hijri (Islamic) calendar, using the Umm al-Qura calendar.
Open calculator →Hijri to Gregorian
Convert a Hijri (Islamic) date to the Gregorian (Western) calendar, using the Umm al-Qura calendar.
Open calculator →Islamic Countdown
Count down to the next Ramadan, Eid al-Fitr, Eid al-Adha, Islamic New Year, Day of Arafah or Ashura, with days, hours, minutes and seconds.
Open calculator →Zakat on Gold
Calculate Zakat due on your gold and silver by weight — enter the grams you own and the current price per gram to get 2.5% of their value.
Open calculator →Nisab
Work out the nisab threshold for Zakat from the current gold and silver prices — the minimum wealth at which Zakat becomes due.
Open calculator →Hijri Age
Find your age in Islamic (lunar) years from your Gregorian date of birth — the Hijri year is shorter, so your Islamic age runs slightly ahead.
Open calculator →Zakat al-Fitr
Work out your household's Zakat al-Fitr (Fitrana) — the charity given before Eid prayer — from the number of people and the local rate per person.
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