Everyday numbers.
Made easy.
From a sale price to your final grade.
Get a clear answer, and see how it adds up.
What are you working out?
Percentage
Find a percentage, work out a share, or calculate percentage change. Get the answer with clear steps.
Open calculatorDiscount
Calculate a sale price, two successive discounts, savings, and optional tax using your own tax rate.
Open calculatorTime duration
Calculate time between two clock times, including overnight periods and breaks, with net decimal hours.
Open calculatorFinal grade
Find what grade you need on your final exam from your current average, target grade, and final weight.
Open calculatorUnit converter
Convert length, mass, and temperature with exact unit definitions, clear formulas, and reversible unit selection.
Open calculatorThe answer is just
the beginning.
Every tool includes a worked example and the formula behind it.
Make sense of the mathA quick answer.
A little more understanding.
Start with your question
Choose a tool, enter your numbers, and calculate.
See how it adds up
Check the steps, copy the result, or print it for later.
Keep your numbers yours
Calculations stay on your device. No accounts or saved history.
Good to know.
20% off, then 10% off. So why isn’t it 30%?
A simple way to understand stacked discounts and find the price you actually pay.
Read the guide Everyday percentagesPercent or percentage points? There’s a difference.
The same change can have two correct numbers. Here’s how to tell them apart.
Read the guide