Clear inputs
Each tool names the values it needs and shows any units or assumptions that matter.
Free calculators, converters & everyday tools
Make the numbers easier to understand.
Use clear, practical tools for everyday maths, finance, time, health, home projects, technology and unit conversions.
Explore by category
Choose a category, or search the full collection of 200 calculators and converters.
Maths
Percentages, geometry, statistics, equations and number tools.
Finance
Formula-based money, savings, loan, pricing and budgeting tools.
Time & Date
Dates, durations, working days and countdown tools.
Health & Fitness
General information calculators for measurements and estimates.
Home & Garden
Area, materials and project-planning tools for the home and garden.
Technology
Downloads, screen measurements, storage and technical calculations.
Conversions
Length, weight, volume, speed, data and other unit converters.
Popular starting points
Every tool shows its inputs, method and important limitations.
Percentage Calculator
Find a percentage of a number. Enter the percentage and the number you want to calculate from.
Open toolVAT Add Calculator
Add a user-entered tax rate to a net amount. This tool does not determine the correct tax rate for any transaction.
Open toolAge Calculator
Calculate age in years, months and days between a date of birth and a chosen date.
Open toolBMI Calculator
Calculate body mass index (BMI) from weight in kilograms and height in metres. BMI is a screening measure, not a diagnosis.
Open toolPaint Calculator
Estimate paint required from area, coverage rate and number of coats.
Open toolMetres to Feet Converter
Convert metres to feet using the selected units.
Open toolLoan Repayment Calculator
Estimate a fixed monthly repayment for a repayment loan using the loan amount, annual interest rate and term.
Open toolDate Difference Calculator
Calculate the number of calendar days between two dates.
Open toolElectricity Cost Calculator
Estimate electricity cost from a device power rating, usage time and electricity price you enter.
Open toolSimple by design
The website is built to make routine calculations easier to check, rather than to replace official sources or professional judgement.
Transparent methods
Calculator pages explain the formula or method used, so you can sense-check the result.
Browser-based calculations
Calculator values are processed in your browser. The site does not require an account to use the tools.
Before relying on a result
Check the values, units and method shown on the relevant page. The calculators are general tools and may not reflect your personal circumstances, current laws, current prices, tax treatment, product specifications, medical needs or safety requirements.
For decisions with legal, financial, tax, medical, engineering or safety consequences, use the relevant official information or obtain advice from an appropriately qualified person.