Scientific Calculator

Trig, logarithms, powers, and memory — all in your browser. No sign-up.

DEG

Scientific calculator — functions reference

Supports standard arithmetic, trigonometry (sin / cos / tan and their inverses in degrees or radians), natural log (ln), base-10 log, square root, powers, and reciprocal. Toggle DEG/RAD for trig functions. Memory operations MC / MR / M+ store and recall a value across calculations. For programmer-mode conversions, try Number Base Converter (dec/hex/bin/oct). For common math, use Percentage Calculator.

Built and maintained by Meet Shah · Last updated 1 August 2026

What this tool is used for

Evaluating an expression with trigonometry and logarithms.
Checking a calculation without reaching for a phone.
Working through a problem with memory and repeated operations.
Switching between degrees and radians for a trigonometry problem.
Confirming a result you reached another way.

Frequently Asked Questions

Why does 2 + 3 × 4 give 20 instead of 14?: It is an immediate-execution calculator, like a desk calculator: pressing × evaluates the pending 2 + 3 straight away. There is no operator precedence and no brackets. Enter 3 × 4 = first and then + 2, or use an expression evaluator for algebraic order.
Why is tan(90°) a huge number rather than an error?: 90° becomes π/2 as a binary double, and no double is exactly π/2. The tangent of that very slightly wrong value is finite: the display shows 16331239353200000. For the same reason sin(180°) reads 1.22464679915e-16 instead of a clean zero.
Why doesn't 0.1 + 0.2 show 0.30000000000000004?: Results are rounded to 12 significant figures before display while an IEEE 754 double carries about 15 to 17, so the artefact is hidden and you see 0.3. The unrounded value is still what gets carried into the next operation.
What is the largest factorial it will compute?: 170!, roughly 7.26 × 10³⁰⁶. 171! exceeds the largest finite double (about 1.8 × 10³⁰⁸) and would come back as Infinity, so the tool refuses it. Negative and non-integer inputs are rejected too — the gamma function is not implemented.
Does the DEG/RAD switch affect the inverse functions?: Yes, in both directions: in DEG mode sin takes degrees and asin returns them; in RAD both use radians. log is base 10 and ln is base e. The mode survives pressing C, so check the indicator whenever a trig result looks impossible.
Why do calculators disagree on an expression like 6/2(1+2)?: Because implied multiplication has no universal precedence — some treat it as binding tighter than division, some do not. The expression is genuinely ambiguous, which is why explicit parentheses are the only reliable answer.

Common errors and gotchas

Leaving the calculator in the wrong angle mode, which is the most common trigonometry error there is.
Relying on the implied precedence rather than parentheses, where implementations differ.
Confusing natural log with log base ten, which are both written as 'log' in different conventions.
Reading floating-point rounding as an error, where a result like 0.9999999 is expected.
Chaining operations and losing track of what is in memory.