How to use the scientific calculator
- Type an expression in the box, for example 2*(3+4)^2/sqrt(9), and press Enter. You can also tap the keypad, which inserts text at your cursor.
- Pick Degrees or Radians before using sin, cos, tan and their inverses.
- Use ANS for the previous answer. Use M+, M-, MR and MC to store and recall a value.
- Click an entry in History to bring its expression back. Press Escape to clear the box.
What you can type
The calculator understands a standard set of operators, functions and constants, and it reads your expression with a real parser, never by running it as code.
- Operators: + - * / ^ (power), ! (factorial), % (percent) and parentheses. The symbols × and ÷ also work.
- Functions: sin, cos, tan, asin, acos, atan, ln (natural log), log (base 10), sqrt, cbrt, abs and exp. Write the argument in parentheses, such as sin(30).
- Constants: pi, e and ans (your last answer). Implicit multiplication works, so 2pi, 2(3+4) and 3sin(30) are fine.
- Scientific notation such as 1.5e-3 is read as a number.
Order of operations
Parentheses come first, then factorial and percent, then powers, then unary minus, then multiplication and division, then addition and subtraction. Powers group from the right, so 2^3^2 is 2^9 = 512. A minus sign in front of a power applies after it, so -2^2 is -4, while (-2)^2 is 4 and 2^-2 is 0.25.
Percent behaves like a handheld calculator
A percent on its own divides by 100, so 50% is 0.5 and 200*10% is 20. When a percent follows a plus or minus, it means a percent of the number before it, so 200+10% is 220 and 200-10% is 180. If you want 200 plus 0.1, write 200+0.1.
Degrees, radians and exact angles
In degrees mode sin(30) is 0.5 and tan(45) is 1. At exact quarter turns the tool returns exact values, so sin(180) and cos(90) show 0 instead of 1.2e-16, and sin(pi) in radians mode is 0. tan(90) is undefined and gives an error rather than a huge number. Inverse functions return degrees or radians according to the switch.
Precision and error messages
Results show up to 12 significant digits, which hides binary floating point noise, so 0.1+0.2 displays 0.3. Very large or small values use notation such as 1.5e+20. Factorials work for whole numbers from 0 to 170. Problems such as dividing by zero, the square root of a negative number, ln(0), unmatched parentheses or an unknown word are explained in plain text. The calculator never shows NaN or Infinity.
Privacy and limits
Your expressions and history stay in this browser tab. They are not saved, uploaded or shared, and they disappear when you close or reload the page. Expressions are limited to 1,000 characters. For solving equations see the quadratic equation solver, and for a spread of numbers use the standard deviation calculator.
Assumptions and limits
- Calculations use standard double-precision arithmetic, which holds about 15 to 17 significant digits. Results are displayed to 12.
- Complex numbers are not supported, so the square root of a negative number and a negative base with a fractional power are reported as errors. Use cbrt for cube roots of negative numbers.
- 0 to the power 0 is treated as 1, as most calculators do.
- Factorial is limited to whole numbers up to 170, because 171! exceeds the largest representable number.
- Memory and history are kept only in memory for this tab and are never sent anywhere.
Frequently asked questions
Why does sin(180) show 0 and not a tiny number?
Computers store pi as an approximation, so a naive sine of 180 degrees returns about 1.2e-16. This calculator recognizes exact multiples of a quarter turn and returns the true value, so you see 0.
Why does 0.1 + 0.2 equal 0.3 here?
Binary arithmetic stores 0.1 and 0.2 inexactly, giving 0.30000000000000004 internally. The display rounds to 12 significant digits, which is far finer than any real measurement and removes that noise.
How do I switch between degrees and radians?
Use the Angle unit buttons above the display. The setting applies to sin, cos, tan and to the results of asin, acos and atan, and it is checked each time you press Enter.
What does the percent key do?
On its own it divides by 100. After a plus or minus it takes that percent of the number before it, so 80-25% gives 60, the same as many pocket calculators.
Does this calculator use eval?
No. It has its own tokenizer and parser that only understand numbers, operators, the listed functions and constants. Anything else is rejected with a message, so pasted text cannot run code.