A simple online calculator for adding, subtracting, multiplying and dividing. Use the on-screen keys or your keyboard, and get a quick answer without installing anything.
Results are estimates for planning. Check the figures before you make a financial or health decision.
How the Basic calculator works
This is an everyday calculator for the four basic operations: addition, subtraction, multiplication and division. You can click or tap the on-screen keys, or type on your keyboard using the number keys and the usual symbols for each operation.
Like a pocket calculator, you enter a number, choose an operation, enter another number and press equals. Everything runs in your browser, so nothing you type is sent to a server.
Computers store decimals in binary, so a few results may show tiny rounding differences, such as the usual quirks with long decimals. For everyday sums these are not visible. Division by zero cannot be calculated.
For anything more advanced, such as brackets, powers, roots or trigonometry, use the Scientific calculator calculator. For fractions, percentages and ratios, the specialist tools on this site show the working for you, which makes it easier to check your answer.
Tips and common mistakes
Check each number as you enter it, since most wrong answers come from a mistyped digit. For a quick sanity check, round the numbers and estimate the answer in your head to see if it looks right.
If you are working out a percentage, use the Percentage of a number calculator rather than doing it by hand. For a longer chain of calculations, write down interim results so you can find any error. If you are adding up a shopping bill or splitting a cost, double-check the final total before relying on it.
Frequently asked questions
Can I use my keyboard?
Yes. Type the digits and the usual operation keys, and press Enter for the result.
Does it follow the order of operations?
It works like a standard pocket calculator, taking one operation at a time. For brackets and the full order of operations, use the scientific calculator.
Is anything I enter stored or sent anywhere?
No. The calculations run in your browser and nothing you type is sent to a server.