Scientific Calculator Online: Trig, Logs, Powers
A free scientific calculator with a keypad and keyboard input: sin, cos and tan in degrees or radians, inverses, log and ln, powers, roots, factorial, percent, π, e, Ans, memory and a history of your last 20 sums.
History
Calculations you make on this visit appear here, newest first.
Scientific Calculator
This free online scientific calculator works like the one in your school bag. Type an expression on your keyboard or tap the keypad, press = or Enter, and the answer appears with 12 significant digits. It handles sine, cosine and tangent in degrees or radians, their inverses, common and natural logarithms, powers and roots, factorials, percentages, the constants π and e, the last answer (Ans), a memory and a history of your last 20 calculations.
How to use the calculator
Steps
- Type into the Expression field, for example
2+3×4, or tap the keys. You can type*for × and/for ÷. - Press Enter,
=or the = key. The result appears below the field and the calculation is added to the history. - Press Escape or AC to clear the field, and Backspace or ⌫ to delete the last character.
- Pick DEG or RAD before using trigonometry. DEG is the default.
- Choose any line in the history to put that expression back in the field.
Order of operations
The calculator follows the usual precedence rules. From the loosest to the tightest binding:
Precedence
- Addition and subtraction, worked left to right.
- Multiplication, division and implied multiplication, such as 2π, 2(3+1) and (1+2)(3+4).
- A leading minus or plus sign. Because powers bind tighter, -2^2 = -4; write (-2)^2 to get 4.
- Powers with ^, which are right-associative: 2^3^2 = 2^9 = 512.
- Factorial ! and percent %, which act on the number just before them. 200×15% is 30.
Brackets you leave open close themselves at the end, so 2×(3+4 gives 14. A closing bracket with no opening bracket is an error.
Functions
Keys
- sin, cos, tan read the angle in the current mode. In DEG mode, multiples of 90° give exact values, so sin(180) is 0 and cos(90) is 0.
- asin, acos, atan return an angle in the current mode. asin(0.5) is 30 in DEG mode.
- log is the base-10 logarithm and ln the natural logarithm: log(1000) = 3 and ln(e) = 1.
- √ is sqrt, ∛ is cbrt and ʸ√x is root(x, n). A negative number has an odd root, so cbrt(-27) = -3 and root(-32,5) = -2.
- n! works for whole numbers from 0 to 170. 170! is about 7.25741561531e+306, the largest factorial a computer double can hold.
- E writes a number in scientific notation: 1.5E3 is 1,500.
Errors you might see
A calculator should never show NaN or Infinity, so each impossible result has a plain message: "Cannot divide by zero.", "ln and log need a number greater than 0.", "No real square root of a negative number.", "asin and acos need a value from -1 to 1.", "Factorial needs a whole number from 0 to 170." and "tan is undefined at odd multiples of 90°." A result larger than about 1.8 × 10³⁰⁸, such as 10^400, shows "The result is too large to show."
Precision
Results are calculated in double precision and printed with 12 significant digits, which hides binary rounding noise: 0.1+0.2 shows 0.3. Very large and very small numbers switch to scientific notation.
Privacy
Nothing is uploaded; every calculation runs in your browser and never leaves your device. The expression is read by a small parser built for arithmetic, and typed text is never run as code.
Related tools
For powers with exact big integers and logarithms in any base, use the Exponent Calculator. The Percentage Calculator handles percent change and percent of a number, and the Fraction Calculator keeps answers as exact fractions.
Frequently asked questions
Why does -2^2 give -4 and not 4?
The power is worked out before the leading minus sign, as on most scientific calculators and in written algebra, so -2^2 means -(2^2) = -4. Type (-2)^2 with brackets to square the negative number and get 4.
How do I switch between degrees and radians?
Use the DEG and RAD toggle above the keypad. DEG is the default. In DEG mode sin(30) is 0.5 and asin(0.5) returns 30; in RAD mode sin(π/6) is 0.5 and acos(0) returns 1.57079632679. Exact angles such as sin(180) in DEG mode show 0, not a tiny rounding error.
What do Ans, MC, MR, M+ and M− do?
Ans holds the last result, so after 2+3 you can type Ans×2 to get 10. The memory keeps one number for the visit: M+ adds the current expression's value, M− subtracts it, MR writes the stored value into the expression and MC sets it back to 0.
How many calculations does the history keep?
The last 20, newest first. Choose an entry to put its expression back in the field and edit it. The history lives only in this browser tab and is cleared when you reload the page.
Why does the calculator show an error instead of a number?
Some results are undefined or too large. Dividing by zero, the log of 0 or less, the square root of a negative number, asin of 2, a factorial of a non-whole number or of more than 170, and tan(90) in degrees all show a plain message. Results beyond about 1.8e308 show 'The result is too large to show.'
Is my calculation sent anywhere?
No. The expression is read by a small parser that runs in your browser. Nothing is uploaded and no typed text is ever run as code.