About this tool
A full-featured scientific calculator that runs in your browser. Supports trigonometric functions (sin, cos, tan and their inverses), logarithms (log₁₀ and ln), exponentials, factorials, square roots, powers, and constants (π, e). Toggle between degree and radian mode for trig calculations.
About this scientific calculator
This in-browser scientific calculator mirrors the function set of a Casio fx-991ES or Texas Instruments TI-30X: 10-digit display, full operator precedence, the trigonometric family with their inverses, base-10 and natural logarithms, exponentials, factorials, square roots, arbitrary powers, the constants pi and e, and parentheses for arbitrary nesting. It accepts both keypad clicks and physical keyboard input, including the standard symbols (+, -, *, /, (, ), ., 0 through 9, Enter to evaluate, Backspace to delete).
The whole expression is evaluated as one string when you press equals, so the order of operations is identical to what you would write on paper. There is no separate stack mode, no RPN. That makes it the right tool for homework, quick engineering checks, currency-free unit math, and basic statistics, without the learning curve of a graphing calculator.
How it works
Each tap appends to a single buffer string. Pressing equals replaces shorthand tokens (sin( becomes Math.sin(, factorial ! becomes a call to a custom factorial routine, pi becomes 3.141592653589793) and runs the result through a sandboxed Function constructor. The sandbox executes inside "use strict" so a stray identifier raises an error instead of silently leaking to the global scope. The displayed result is rounded to 10 decimal places, which is roughly the precision limit of IEEE 754 double-precision arithmetic for non-trivial trigonometric inputs.
DEG to RAD: theta_rad = theta_deg * pi / 180 log(x) = log_10(x) = ln(x) / ln(10) n! = 1 * 2 * 3 * ... * n for integer n in [0, 170] x^y = Math.pow(x, y) respects sign of x, returns NaN for negative^non-integer
Worked example: projectile range
A javelin is thrown at 28 m/s at an angle of 38 degrees above the horizontal on flat ground. Standard range formula: R = v^2 * sin(2 theta) / g with g = 9.81 m/s squared.
- Set mode: DEG (the angle is in degrees).
- Square the velocity: 28 squared = 784.
- Double the angle: 2 times 38 = 76 degrees.
- Take the sine: sin(76) = 0.9703 (rounded to 4 places).
- Multiply: 784 times 0.9703 = 760.7.
- Divide by g: 760.7 divided by 9.81 = 77.54.
Function reference
| Function | Notation | Domain | Notes |
|---|---|---|---|
| Sine, cosine, tangent | sin, cos, tan | any real | Argument in DEG or RAD per mode. |
| Inverse trig | asin, acos, atan | [-1, 1] for asin and acos | Returns in DEG or RAD. |
| Log base 10 | log | x greater than 0 | log(1000) = 3. |
| Natural log | ln | x greater than 0 | ln(e) = 1. |
| Exponential | exp or e^x | any real | exp(0) = 1; exp(1) = 2.7183. |
| Power | x^y | x positive for non-integer y | 2^10 = 1024. |
| Square root | sqrt | x greater than or equal to 0 | sqrt(2) = 1.4142. |
| Factorial | n! | integers 0 to 170 | 171! overflows to Infinity. |
| Constants | pi, e | n/a | 15 significant digits. |
Common pitfalls
- DEG vs RAD confusion. Around 90 percent of "wrong answers" come from running a physics formula in DEG or a survey formula in RAD. Always check the mode indicator before sin, cos, or tan.
- Unary minus precedence. Writing minus 3 squared gives 9 (the minus binds tightly). To get minus 9 wrap as zero minus 3 squared, or write minus open-paren 3 squared close-paren.
- Logarithm base.
logon this calculator is base 10, matching most engineering and chemistry conventions.lnis base e. Scientific papers sometimes uselogfor natural log. - Floating-point residue. Values like sin(180) display as 1.22e-16 instead of zero. That is the IEEE 754 limit, not a bug.
- Implied multiplication. Casio devices treat
2(3)as2 * 3. JavaScript treats it as a function call to2, which is an error. Always type the asterisk. - Factorial of non-integer. 2.5! is mathematically the gamma function. This calculator returns NaN for non-integer factorials.
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Frequently asked questions
What functions does this scientific calculator support?
Trigonometric functions sin, cos, tan and their inverses arcsin, arccos, arctan; logarithms log base 10 and natural log ln; exponential e to the x; factorial of integers up to 170 (the JavaScript Number.MAX_VALUE cap); square root and arbitrary powers x to the y; the constants pi (3.14159265358979) and e (2.71828182845904); plus full parentheses for grouping and standard operator precedence.
How do I switch between degrees and radians?
Tap the DEG/RAD toggle at the top of the keypad. DEG is the default and is correct for textbook problems, navigation, and surveying. RAD is required for calculus, physics formulas, and any expression involving radians of pi. In DEG mode, sin(90) returns 1. In RAD mode, sin(pi/2) returns 1. Mixing the two modes is the single most common reason a result looks wrong.
Why does sin(180) return 1.22e-16 instead of zero?
Floating-point math cannot represent pi exactly. Internally the calculator converts 180 degrees to pi radians, but pi stored in double precision IEEE 754 is off by roughly 10 to the negative 16, so sin of that slightly-off value is the same small residual instead of a clean zero. Round results to 10 decimal places or use the rounding toggle to display 0 for any value below 1e-10.
What is the largest factorial this calculator can compute?
170 factorial, which is approximately 7.257 times 10 to the 306. At 171 factorial the result exceeds Number.MAX_VALUE (1.797e308) and JavaScript returns Infinity. For larger factorials use Stirling's approximation: ln(n!) is approximately n times ln(n) minus n plus 0.5 times ln(2 pi n), or fall back to a big-integer library.
Does the calculator respect operator precedence?
Yes. Expressions follow the standard PEMDAS or BODMAS order: parentheses, exponents, multiplication and division (left to right), addition and subtraction (left to right). So 2 plus 3 times 4 returns 14, not 20. Unary minus binds tightly, so minus 2 squared returns 4, matching the convention used by Casio, Texas Instruments, and Wolfram Alpha.
Last updated 2026-05-28.