Trigonometric Functions Calculator (sin, cos, tan) — Free
Runs 100% in your browser — your files never leave your device.
Sine, cosine, tangent — and arcsine, arccosine, arctangent — without digging through scientific-calculator menus. Pick the function, choose degrees or radians, type the angle (or the ratio, for the inverse functions) and read the result. Inputs outside a function's domain explain the problem instead of showing NaN.
How it works
- 1
Pick the function
sin, cos, tan — or asin, acos, atan to go from a ratio back to an angle.
- 2
Choose the angle unit
Degrees or radians, for both input and output of the inverse functions.
- 3
Type the value
The result appears live; out-of-range inputs explain themselves.
About this tool
Sine, cosine, and tangent computed
Enter an angle and the tool returns sine, cosine, and tangent with full precision — the three ratios that describe every right triangle and every oscillation. Degrees or radians, your choice; the functions expect the correct unit and the tool removes that ambiguity.
Where trigonometry actually appears
Screen coordinates and game movement, audio waveforms and signal processing, roof pitches and ramp slopes in construction, GPS and navigation math, and the physics of anything that swings, spins, or waves. The functions map angles to ratios — everything else builds on them.
Degrees versus radians
Degrees divide the circle into 360; radians measure arc length where a full circle is 2π. Programming libraries default to radians — converting with the radians-degrees tool before computing saves the classic wrong-answer-by-57-degrees bug.
Frequently asked questions
Why is tan(90°) undefined?
Tangent is sine divided by cosine, and cosine hits zero at 90 degrees — division by zero. The tangent curve runs to infinity approaching that angle, which is the geometric reality the calculator reflects.
What does a negative sine mean?
The function extends past the first circle-quarter — negative sine means the angle sits in the third or fourth quadrant where the ratio points below the reference axis. Sign carries the quadrant information.
Do the results use degrees or radians internally?
The tool converts your input to the unit the math needs and computes exactly — pick degrees or radians on input, and the result is correct either way.