Calculator

Open Calculator and pick the keypad that matches the job. Standard handles short arithmetic, Scientific evaluates expressions with powers or trigonometry, and Programmer works with integer bases and bits. The page is a free online calculator, so there is no app to install and no account to create.

Start with the least complicated mode

A standard calculator is usually the right choice for a bill, a quick total or one percentage. AC resets the whole operation; C clears only the number currently being entered. The wider zero key and four-operation layout keep this mode close to a simple calculator.

• Choose Standard for addition, subtraction, multiplication, division, sign changes and percentages.
• Choose Scientific for parentheses, roots, powers, logarithms, factorials and angle functions.
• Choose Programmer when the input is an integer written in BIN, OCT, DEC or HEX.

The scientific calculator with functions such as sin, cos, tan, log, ln, √, xʸ, π and e also covers the common work expected from an engineering calculator.

The percent key follows the operator

For addition and subtraction, the first number becomes the percentage base. Entering 500 - 20 % returns 400 because 20 percent of 500 is 100. With multiplication or division, the percentage is treated as a ratio: 50 × 10 % returns 5, while 50 ÷ 10 % returns 500. Pressing 20 % by itself produces 0.2.

A dedicated percentage tool is clearer for reverse percentages, percentage change and several discounts in sequence. The percent key here is meant for the short pattern familiar from a handheld calculator.

Scientific results depend on order and angle unit

The scientific calculator follows mathematical precedence. It reads 2 + 3 × 4 as 14, but (2 + 3) × 4 as 20. Exponents associate from the right, so 2^3^2 is 512; negative exponents such as 2^-2 are accepted as well.

A function key uses the complete expression on the display. Type 2 + 3 and then press √ to calculate the square root of 5, rather than the square root of the first number. Adding π or e after a number inserts multiplication automatically.

Select DEG when an angle is given in degrees and RAD when it is given in radians. In DEG, sin(30) is 0.5. tan(90°), division by zero and the square root of a negative number return an error. Factorial accepts whole numbers from 0 through 20, rather than silently rounding a decimal input.

Decimal results are shown with up to 12 places to hide binary floating-point noise. Very small or very large values switch to scientific notation, so calculations requiring more precision should account for the displayed rounding limit.

Programmer arithmetic and bit operations are different

Changing BIN, OCT, DEC or HEX keeps the integer value and redraws it in all four bases. Regular arithmetic uses exact integer values within the input length shown by the keypad; division discards the fractional remainder. AND, OR, XOR, NOT and the two shift buttons use a 32-bit unsigned bit pattern. That detail explains why NOT can produce a large positive decimal value.

Use Calculator with a keyboard or touch

Digits and +, -, *, / can be typed directly. Enter or = evaluates, Escape clears, and Backspace removes the latest character; Scientific also accepts typed parentheses. The latest 20 Standard results remain in the history panel, where any result can start the next operation.

Keeping this calculator online in an open browser does not send expressions to the server. History is stored only in that browser. On a shared computer, use Clear in the history panel before leaving the page.