A full scientific calculator with trigonometry, logarithms, powers, roots, and constants — supports brackets, degree/radian mode, keyboard input, and a running calculation history.
Press = or Enter to evaluate.
Before electronic calculators, scientists and engineers relied on slide rules and printed logarithm tables to perform the same trigonometric, logarithmic, and exponential calculations this tool handles instantly. The first handheld scientific calculators arrived in the early 1970s and were revolutionary precisely because they collapsed hours of manual table-lookup work into a single button press — the same functions (sin, cos, tan, log, ln, powers, roots) that defined those early devices are still the core feature set expected of any scientific calculator today, this tool included, because they remain the fundamental building blocks of trigonometry, calculus, and applied science calculations.
Rather than calculating step-by-step as you press each button (the way a simple four-function calculator works), this tool uses 'algebraic entry' — you build a complete expression as text, exactly as you'd write it on paper, and the calculator parses and evaluates the whole thing at once when you press equals. Internally, this happens in two stages: tokenizing (scanning your expression character by character to identify numbers, operators, function names, and parentheses) and parsing (assembling those tokens into the correct calculation according to mathematical order-of-operations rules, using a technique called recursive-descent parsing). This two-stage approach is exactly how programming language interpreters and compilers process code, just applied here to arithmetic expressions instead — and it's what makes correctly handling nested parentheses and functions like sin(cos(30)) possible.
Angles can be measured in different units, and trigonometric functions need to know which unit you're using to give a correct answer. A degree divides a full circle into 360 equal parts (an ancient convention, likely tied to the roughly 360-day year used by Babylonian astronomers). A radian instead measures an angle by the length of the arc it traces on a unit circle, making a full circle exactly 2π radians (about 6.28) — a less intuitive everyday unit, but the one that makes calculus formulas involving trig functions dramatically simpler, since derivatives and integrals of sin and cos only take their cleanest form when the input is in radians. This calculator defaults to Degree mode for everyday familiarity, with a one-click toggle to Radian mode for calculus, physics, and engineering work.
A few expression patterns come up constantly: right-triangle trigonometry (sin, cos, and tan of a known angle to find a missing side length, in Degree mode for typical geometry problems), exponential growth and decay (using e and ln for continuous compounding or radioactive decay calculations), the Pythagorean theorem and distance formulas (using sqrt and x² together, like sqrt(a^2+b^2)), and general algebraic simplification of a multi-step formula in one shot rather than calculating intermediate results by hand and re-entering them. The calculation history exists specifically to support this last pattern — letting you glance back at a previous result while building the next expression, without losing your place.
Scientific Calculator handles trigonometry, logarithms, and powers in one expression. These related calculators cover other common everyday math.