Basic Calculator - DigiKitApp

Evaluate basic mathematical expressions.

When should you use this?

Use this for quick, everyday arithmetic, addition, subtraction, multiplication, division.

When shouldn't you use this?

If you need scientific calculation (exponents, square roots, trigonometry) or multi-step financial math, this simple tool isn't enough; use one of the site's specialized calculators (loan, ROI) instead.

Step-by-step

Type your calculation on one line in the Expression (e.g. (2+3)*4) field. Use + to add, - to subtract, * to multiply and / to divide.
Wrap whatever should be worked out first in parentheses. Without them, multiplication and division happen before addition and subtraction.
Use a period for decimals, so 12.5 rather than 12,5.
Click Run and the answer appears below the form. Edit the expression and run it again to try other numbers.

Example

You had dinner with friends. The bill is 84, you want to leave a 12 tip, and there are four of you. Enter (84+12)/4 and the result is 24, so each person pays 24. If you forget the parentheses and type 84+12/4, the calculator divides 12 by 4 first and gives you 87. Order-of-operations mistakes like this are easy to catch if you glance at the answer and ask whether it makes sense.

Which operations are supported?

The tool accepts addition (+), subtraction (-), multiplication (*), division (/), parentheses and the decimal point. An expression can contain only digits, these signs, % and spaces; any other character gives an “Unsupported expression” error. Writing the multiplication sign twice raises to a power: 2**3 = 8. Note: the % sign is a modulo (remainder) operation, not a percentage; 7 % 3 = 1 and 10 % 4 = 2. For a percentage use multiplication: for 15% of 200, type 200 * 15 / 100 = 30.

When calculating

Use a dot as the decimal separator: 1.5. A comma gives an error.
Because computers store numbers in binary, 0.1 + 0.2 gives 0.30000000000000004; this is not a bug but the known behaviour of floating-point arithmetic. Round the result for money.
Division by zero does not raise an error; it returns Infinity.
For a percentage increase or a discount the site has separate percentage and discount calculators; this tool is only for the four basic operations.

Things to keep in mind

Don't type thousands separators. Writing 1,250 or 1.250 won't be read as one thousand two hundred fifty.
Spell out percentages as multiplication. To get 15 percent of an amount, multiply by 0.15. To add 15 percent, multiply by 1.15.
Because of the way computers store decimals, very long fractional results can show tiny rounding differences in the last digits. Round money to two places.
Division by zero is undefined, so don't expect a meaningful number from it.

For anything beyond a single line of arithmetic, like loan payments or returns over time, a dedicated calculator will save you from building long formulas by hand.

Frequently asked questions

How accurate are the results?

Calculations use standard mathematical formulas; for official purposes (tax, loan applications, etc.) we recommend confirming current rates with the relevant institution.

Are the numbers I enter saved?

No, no numbers are sent to a server; the calculation happens entirely in your browser.

Can I use this on mobile?

Yes, the tool works smoothly on all screen sizes.