Online Calculator

Click the buttons or type numbers and operators straight from your keyboard. It handles parentheses and percentages (%), and your calculation history is saved in this browser.

How to use the Online Calculator

Click the number buttons on screen or type an expression on your keyboard, for example 1200*3+500.
While you type, a preview of the running result appears on the display.
Press the = button or the Enter key to get the final result and save it to your calculation history.
With a result showing, pressing an operator carries on from that result; pressing a number starts a new calculation.
Click any entry in the history below to bring back an earlier result and keep calculating from it.

Order of operations: multiplication and division first

This calculator follows the standard mathematical order of operations (often taught as PEMDAS in the US or BODMAS/BIDMAS in the UK, Canada and Australia). Anything in parentheses is worked out first, then multiplication and division, and finally addition and subtraction, from left to right.

Expression	Order of calculation	Result
`2+3×4`	3×4=12 first, then 2+12	14
`(2+3)×4`	Parentheses 2+3=5 first, then 5×4	20
`100-20÷4`	20÷4=5 first, then 100-5	95
`-3×-2`	Multiplying two negative numbers	6

Some basic phone and desk calculators work through each step as you enter it (so 2+3×4 gives 20), which means their results can differ from this one. If you want a calculation done in the order you type it, use parentheses.

How to calculate percentages (%) with this calculator

The % key works in two different ways depending on where you use it.

On its own: it divides the number by 100. 15% = 0.15, and 250×8% = 250×0.08 = 20.
After a plus or minus: it is treated as a percentage of the value before it. 200+10% = 200 + 20 = 220, and 50-15% = 50 - 7.5 = 42.5.

This makes it easy to add or take off a percentage in one step, such as a price increase, sales tax (120+8% = 129.6) or a discount. For percentage change and other ratios, try the percentage calculator, and to work out sale prices, use the discount calculator.

Why 0.1+0.2 doesn't show 0.30000000000000004

Computers store numbers in binary, so decimals like 0.1 that can't be represented exactly in binary pick up a tiny rounding error. That's why many programming languages return 0.30000000000000004 for 0.1+0.2.

This calculator rounds results to 12 significant digits, which removes these errors. That is more than accurate enough for everyday money and measurement math. Very large numbers (10 quadrillion and up) and very small decimals are shown in exponential notation, such as 1.23e+16.

Tips for fast keyboard calculations

Numbers copied from Excel, Google Sheets or a text file still work even if they include thousands separators (1,200).
On your keyboard, * means multiply (×) and / means divide (÷). A numeric keypad makes entry even faster.
If you make a mistake, press Backspace to delete one character, or Esc to clear everything.
Your history keeps up to the 30 most recent calculations. It is stored only in this browser and is never shared with anyone.

Frequently asked questions

Can this online calculator handle parentheses?

Yes. Use ( and ) to calculate part of an expression first, and you can nest parentheses inside each other as many levels deep as you need.

What happens if I divide by zero?

Division by zero is undefined in math, so instead of a result the calculator shows the message "Can't divide by zero."

Where is my calculation history stored?

Only in your browser's local storage. It is never sent to a server, and clicking "Clear history" deletes it immediately.

Does it work on my phone?

Yes. The buttons resize to fit your screen, so you can use it in a mobile browser just like a regular calculator. Add a shortcut to your home screen to open it like an app.

Is the calculator free to use?

Yes. It's completely free, needs no sign-up or download, and runs entirely in your browser.

Calculation history