XYCalc

Scientific Calculator

A free online scientific calculator: sin, cos, tan and inverses in degrees or radians, logs, powers, roots, factorials, π and e, with history.

New: please check your results.

XYCalc
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What it does

A full scientific calculator in your browser. Type or tap a whole sum, such as 2 × sin(30) + √16, and see the answer as you go. It covers trigonometry in degrees or radians, natural and base-10 logs, powers and roots, factorials, π and e, and follows the standard order of operations.

Just need the basics? Switch Mode to Basic for a simpler keypad with percent and memory keys.

How to use it
Mode

Basic shows a simple keypad with percent and memory keys. Scientific adds trigonometry, logs, powers, roots, factorials, π and e. Advanced adds +VAT and −VAT, answers as fractions (a/b) and a fixed number of decimal places (Fix); its extra keys scroll while the number pad and the screen stay put.

Angles in

Whether sin, cos and tan (and their inverses) use degrees or radians. School maths and most practical work use degrees; calculus uses radians.

Sum

Tap the keys or type with your keyboard: + − × ÷ (or * and /), ^ for powers, ! for factorials, and brackets. Enter or = saves the answer to your history; tap a past sum to use it again.

Common uses

The formula
Order: brackets, then functions and powers, then × and ÷, then + and −Powers work right to left: 2^3^2 = 2^9 = 512−2^2 = −4 (the power first); use (−2)^2 for 4A number next to a bracket, π or a function multiplies: 2π, 3(4), 2sin(30)n! = 1 × 2 × … × n, for whole numbers 0 to 170

Where:

ln
natural log (base e)
log
log base 10
sin⁻¹, cos⁻¹, tan⁻¹
inverse functions: the angle with that sin, cos or tan

Answers are shown to 12 significant figures. Very large or very small answers use scientific notation, e.g. 1.2E20 means 1.2 × 10²⁰.

Worked example

For 2 × sin(30) + √16, in degrees:

  • sin 30° = 0.5, so 2 × sin(30) = 1
  • √16 = 4
  • 1 + 4 = 5

Questions people ask

Should I use degrees or radians?

Degrees for everyday geometry, building and most school maths (a right angle is 90°). Radians for calculus, physics formulas and anything involving π directly (a right angle is π/2). If sin(30) doesn't give 0.5, you're probably in radians.

What's the difference between log and ln?

log is base 10 (log 1000 = 3, because 10³ = 1,000). ln is the natural log, base e ≈ 2.71828 (ln e = 1). Both only work for numbers above 0.

Why does tan(90) give an error?

Because tan 90° has no value: it's sin 90° ÷ cos 90°, which is 1 ÷ 0. Graphs of tan shoot off to infinity there. The same happens at 270°, 450° and so on.

Last checked 31 October 2026 · Last rev. 31 October 2026 · f3f7