Free online calculator

This is a basic online calculator for the math you do every day: totals, splitting a bill, unit prices, quick percentages. It handles addition, subtraction, multiplication, division, percentages and parentheses, and it follows the normal order of operations, so 2 + 3 × 4 gives 14, not 20.

As you type, a preview line shows the answer before you press equals. After you press = (or Enter), the result stays on the display and the calculation is saved to the history list, where one tap puts it back on the display for editing.

Everything happens in your browser; nothing you type is sent to a server. The history lives only in the current tab and is cleared when you reload the page.

You don't have to click the buttons. The display is a normal text field, so you can type directly:

Key	Action
0–9 and .	Numbers and decimal point
+ − * /	Add, subtract, multiply, divide
^	Power (2^10 = 1,024)
( )	Parentheses
%	Percent
Enter or =	Calculate
Esc	Clear

You can paste numbers with thousands separators such as 1,250.75; the commas are ignored. If you start typing a number right after a result, a new calculation starts. If you type an operator, the calculation continues from the result.

The % key follows the habit of pocket calculators, which makes everyday percentage math quick:

• a + b% adds b percent of a: 80 + 15% = 92 (a price plus a 15% tip).
• a − b% subtracts b percent of a: 120 − 25% = 90 (a 25% discount).
• a × b% gives b percent of a: 250 × 8% = 20.
• On its own, b% means b / 100: 7% = 0.07.

So you can find a sale price, add sales tax or work out a tip without converting percentages to decimals first. For percentage change, percent of a total and reverse percentages, a dedicated percentage calculator gives more detail.

The calculator uses the standard order of operations (often taught as PEMDAS): parentheses first, then exponents, then multiplication and division from left to right, then addition and subtraction from left to right.

A few things that trip people up:

• Missing parentheses. (12 + 8) / 4 = 5, but 12 + 8 / 4 = 14.
• Negative numbers and powers. −3^2 is −9 because the power is applied first; write (−3)^2 to get 9.
• Dividing by zero shows an error instead of a number.
• Very large results switch to scientific notation (for example 1.2e15) so they fit on the display.

If you need trigonometry, logarithms, roots or factorials, switch to the scientific calculator, which uses the same engine with more keys.

A few calculations people use this page for, with the keystrokes:

• Split a restaurant bill: (86.40 + 18%) / 4 = 25.49 per person with an 18% tip.
• Sales tax: 249.99 + 7.25% = 268.11.
• Unit price: 7.98 / 24 = 0.3325, about 33 cents per can.
• Hourly to yearly pay: 22.50 × 40 × 52 = 46,800.
• Miles per gallon: 312 / 9.6 = 32.5.

Rounding is up to you: the display shows up to 10 decimal places, so round money to the nearest cent yourself, or use the rounding calculator for a specific rule. For gas mileage and trip costs there is a dedicated gas mileage calculator.