Scientific Calculator
Free online scientific calculator: trigonometry in degrees or radians, powers, roots, logarithms, factorials and history. Follows the real order of operations.
You can also type with the keyboard: Enter calculates, Esc clears, ^ is a power and ! a factorial.
What it does
A scientific calculator that follows the order of operations taught in school: powers before signs and products, and products before sums. It works in degrees or radians, has trigonometric and inverse functions, natural and base-10 logarithms, roots, powers, factorials, the constants π and e, and keeps a history of your calculations. You can type the whole expression, such as 2sin(30) + √16, and the result appears as you type.
How to use it
- Type the expression with the keyboard or the buttons. Multiplication can be implicit: 2π or 3(4+1).
- Choose DEG or RAD for the trigonometric functions.
- Press = or Enter. Ans reuses the last result, and the history lets you reopen any previous calculation.
The arithmetic runs in your browser. Nothing you type is sent anywhere and nothing is stored, so you can use these with real numbers.
Frequently asked questions
Why is −2² equal to −4 and not 4?
Because a power is calculated before the minus sign, as in standard mathematical notation: −2² means −(2²). To square a negative number, use parentheses: (−2)² = 4. The same rule makes 2^3^2 equal to 2^9 = 512, since powers are grouped from the right.
Should I use degrees or radians?
Use degrees (DEG) for angles in everyday geometry, where a full turn is 360. Use radians (RAD) in calculus and physics, where a full turn is 2π. In degree mode the notable angles give exact results: sin(30) is exactly 0.5 and tan(90) is reported as undefined.
How much is 6 ÷ 2(1 + 2)?
It is 9. Division and multiplication, including the implicit multiplication of 2(1 + 2), have the same priority and are done from left to right: 6 ÷ 2 = 3, and 3 × 3 = 9. If you mean 6 divided by the whole of 2(1 + 2), write 6 ÷ (2(1 + 2)) = 1.
How does the % key work?
On its own, a percentage is divided by 100: 10% is 0.1 and 200 × 10% is 20. After a plus or minus sign it works like a shop calculator: 50 + 10% adds 10% of 50 and gives 55.
How precise are the results?
Results are shown with up to 12 significant digits, which removes the tiny rounding errors of computer arithmetic, so 0.1 + 0.2 gives 0.3 and not 0.30000000000000004. Very large or very small numbers are shown in scientific notation.
Wikipedia — Scientific calculator
Wikipedia — Order of operations