Math & Dates Scientific calculator
A full scientific calculator with trigonometry, logarithms, powers, roots and factorials. Type expressions directly or use the keypad.
0
Ready. Runs locally on your device.
Your files stay on your device. The tool works directly in your browser, using your device to process your files. Nothing is sent to our servers, and we never receive, store, or see your files or figures.
Share result
Cite
Cite this page
Reembun. (2026, July 27). Scientific calculator. https://reembun.com/scientific-calculator
How to use it
Type the expression
Write it the way you would on paper, such as 2^10 or sin(45). The keypad enters the same thing if you prefer buttons.
Set the angle unit
DEG or RAD changes what sin, cos and tan mean. It is the most common cause of a wrong answer here, so check it before you trust one.
Reuse earlier work
Ans carries the last result into the next expression, and clicking any line of the history puts it back in the input.
Copy the result
Copy result takes the answer, and the expression stays on screen so you can see how you got it.
Order of operations
The parser follows standard precedence, from tightest to loosest:
- Brackets
( ) - Functions such as
sin,ln,sqrtand the rest - Factorial
! - Exponentiation
^, right-associative - Unary minus
- Multiplication, division, modulo
× ÷ % - Addition and subtraction
+ −
Right-associativity of ^ means 2^3^2 evaluates as 2^(3^2) = 512, not (2^3)^2 = 64. This is the mathematical convention.
Supported functions
| Category | Functions |
|---|---|
| Trigonometric | sin cos tan asin acos atan |
| Hyperbolic | sinh cosh tanh |
| Logarithmic | ln (base e), log (base 10), log2 |
| Roots and powers | sqrt cbrt exp ^ |
| Rounding | round floor ceil abs sign |
| Constants | pi e tau |
Factorial is written postfix: 5! gives 120. It is defined for non-negative integers only, and overflows the double-precision range above 170.
Worked examples
Compound growth. 1000 * 1.07^10 → 1,967.15
Hypotenuse. sqrt(3^2 + 4^2) → 5
Half-life. 100 * 0.5^(30/12) → 17.68 (100 units after 30 months, 12-month half-life)
Angle from a slope. In DEG mode, atan(1/2) → 26.565°
Combinations. 10! / (3! * 7!) → 120
Decibels. 20 * log(5) → 13.98
Implicit multiplication
A number followed directly by a bracket, a constant or a function is treated as multiplication: 2(3+1) is 8, 3pi is 9.4248, 2sqrt(9) is 6. This is how people write maths by hand, and supporting it removes a common source of transcription errors.
Why your input is never run as code
Most in-browser calculators take a shortcut and hand whatever you type straight to the browser to be executed. That works, but it means anything typed into the box is run as code.
This calculator reads your input as arithmetic and nothing else, so arithmetic is the only thing that can ever happen. It also means errors can be specific: an unbalanced bracket says so, rather than producing a cryptic syntax error or a silent, meaningless result.
Degrees and radians
The DEG/RAD switch converts on the way in for sin, cos and tan, and on the way out for asin, acos and atan. Hyperbolic functions are unaffected, since their argument is not an angle. Getting caught in the wrong mode is the most common cause of a trigonometric answer that looks nonsensical, so check the switch before checking your working.
Common questions
Why does −3² give −9 instead of 9?
Because exponentiation binds more tightly than the minus sign, so −3² reads as −(3²). This matches standard mathematical notation and how Python and most textbooks behave. Spreadsheets like Excel do the opposite and return 9. If you want the square of negative three, write (−3)².
Do the trig functions use degrees or radians?
Whichever you select with the DEG/RAD switch. The default is degrees, since that is what most people arrive wanting. The switch affects both directions, so in DEG mode asin(0.5) returns 30 rather than 0.5236.
Can I type an expression instead of pressing keys?
Yes, and it is usually faster. Type something like 2^10 + sqrt(144) and press Enter. Implicit multiplication works too, so 2(3+1) and 2pi are both understood.
Is my input sent anywhere?
No. The expression is worked out on this page, and what you type is never executed as code. It is read as arithmetic and nothing else.
Last reviewed
