Students & Education
Scientific Calculator
A full scientific calculator with trigonometry, logarithms, powers and parentheses.
Keyboard: type digits and operators, Enter to calculate, Backspace to delete, Escape to clear. Percent means divide by 100, so 50% is 0.5.
Free to use. No sign-up required.
How it works
Type or tap an expression and the calculator evaluates it as a whole, respecting the normal order of operations: parentheses first, then powers, then multiplication and division, then addition and subtraction.
The expression is parsed into a syntax tree and evaluated directly. It is never passed to the browser’s eval, so nothing you type can execute as code.
The DEG and RAD toggle controls how the trigonometric functions read their input. In DEG, sin(30) is 0.5. In RAD, sin(30) is about −0.988. Switching the toggle re-evaluates the current expression immediately.
On a desktop keyboard you can type digits, operators, parentheses and a decimal point, press Enter to evaluate, Backspace to delete and Escape to clear.
Formula
Order of operations
( ) → x! → xʸ → × ÷ → + −
Powers are right-associative, so 2^3^2 is 2^(3^2) = 512.
Percent
x% = x ÷ 100
Postfix operator, so 50% is 0.5 and 200 × 15% is 30.
Degrees to radians
radians = degrees × π ÷ 180
Applied automatically to sin, cos and tan when DEG is selected.
Worked examples
(12 + 8) × 3 ² = 180
The parentheses resolve to 20, the square applies to 3 giving 9, and 20 × 9 = 180.
sin(30) in DEG = 0.5
Switch to RAD and the same expression gives −0.988, because 30 is then read as 30 radians.
5! + √144 = 132
The factorial of 5 is 120 and the square root of 144 is 12.
Frequently asked questions
Is eval() used to work out the answer?
No. The expression is tokenised and parsed into a syntax tree, then evaluated by walking that tree. Only numbers, operators and the supported functions are recognised, so arbitrary code cannot run.
How does the percent key behave?
It is a postfix operator meaning divide by one hundred. So 50% evaluates to 0.5, and 200 × 15% gives 30. It does not guess at "add 15 percent" the way some pocket calculators do, because that behaviour is ambiguous.
What happens with an invalid expression?
You get a short message explaining the problem - an unclosed bracket, a missing number, a division by zero - instead of NaN or a silent wrong answer.
Are there limits on factorials?
Factorials are only defined here for whole numbers from 0 to 170. Above 170 the result exceeds what a double-precision number can hold, so the calculator says so rather than returning Infinity.