Why are tan(90°) and cot(0°) shown as undefined?

These functions are reciprocals of cos and sin respectively, and they divide by zero at those angles. Mathematically the value does not exist, so the tool reports "undefined" instead of a giant floating-point number.

What is csc, sec, and cot?

They are the reciprocal trig functions: csc = 1/sin, sec = 1/cos, cot = 1/tan. They are used in calculus identities and integral substitutions.

Does the calculator handle negative angles?

Yes. Negative angles are valid. sin(−x) = −sin(x), cos(−x) = cos(x), and the other functions follow from those.

What about angles larger than 360°?

Trig functions are periodic. The tool computes them directly; the quadrant label is based on the angle reduced mod 360°.

How precise are the values?

Values are rounded to six decimal places by default. The underlying calculation uses the browser’s native Math.sin / Math.cos, which is IEEE-754 double precision.

Yes. The calculator is entirely client-side, free to use, with no account or limit.

Trigonometry Calculator

sin, cos, tan, csc, sec, cot for any angle — degrees or radians — with quadrant.

Written by Golam Rabbani, Founder & Lead Engineer

This interactive tool requires JavaScript. Read the formula and worked example below; you can compute the result by hand.

How to use this trigonometry calculator

Enter the angle value.
Choose the unit: degrees or radians.
Press Calculate. The tool returns sin, cos, tan, csc, sec, and cot, along with the equivalent angle in the other unit and the quadrant.
Use Copy to copy all six values to your clipboard.
Press Reset to clear the input and start a new calculation.

About this trigonometry calculator

The trigonometry calculator computes the six trigonometric ratios — sine, cosine, tangent, cosecant, secant, and cotangent — for any angle. Enter the angle in degrees or radians and the tool reports all six values, the angle in both units, and the quadrant it falls in. Inputs outside the standard 0–360° range are accepted and normalised, so 405° returns the same values as 45°.

As a worked example, enter 30° (degrees mode). The tool returns sin 30° = 0.5, cos 30° ≈ 0.866025, tan 30° ≈ 0.57735, csc 30° = 2, sec 30° ≈ 1.154701, cot 30° ≈ 1.732051. The angle is also shown as π/6 ≈ 0.523599 rad and labelled as falling in quadrant I.

At angles where a function is undefined — tan and sec at 90° and 270°, cot and csc at 0° and 180° — the tool returns the string "undefined" rather than Infinity or NaN. This keeps results readable and avoids the noisy "1e16" output that would otherwise appear due to floating-point rounding near singularities.

FAQ

Why are tan(90°) and cot(0°) shown as undefined?: These functions are reciprocals of cos and sin respectively, and they divide by zero at those angles. Mathematically the value does not exist, so the tool reports "undefined" instead of a giant floating-point number.
What is csc, sec, and cot?: They are the reciprocal trig functions: csc = 1/sin, sec = 1/cos, cot = 1/tan. They are used in calculus identities and integral substitutions.
Does the calculator handle negative angles?: Yes. Negative angles are valid. sin(−x) = −sin(x), cos(−x) = cos(x), and the other functions follow from those.
What about angles larger than 360°?: Trig functions are periodic. The tool computes them directly; the quadrant label is based on the angle reduced mod 360°.
How precise are the values?: Values are rounded to six decimal places by default. The underlying calculation uses the browser’s native Math.sin / Math.cos, which is IEEE-754 double precision.
Is it free?: Yes. The calculator is entirely client-side, free to use, with no account or limit.