Trigonometry Calculators
Degrees to Radians Converter
Convert degrees to radians or radians to degrees instantly. See the formula applied step-by-step. Includes a reference table of all common unit circle angles. Free, no sign-up.
Inverse Trig Calculator
Find arcsin, arccos, arctan, arccsc, arcsec, and arccot for any value. Results in degrees and radians. Principal value ranges shown. Free inverse trig calculator.
Law of Cosines Calculator
Find any side or angle of a triangle using the Law of Cosines. Enter SAS to find the missing side, or SSS to find all angles. Full solutions with formulas shown. Free tool.
Law of Sines Calculator
Solve oblique triangles with the Law of Sines. Enter AAS, ASA, or SSA values and see full results for all sides and angles. Ambiguous case handled automatically. Free calculator.
Right Triangle Calculator
Solve a right triangle from any two known values. Find all sides, all angles, perimeter, and area instantly with step-by-step formulas shown. Free calculator, no sign-up needed.
Sin Cos Tan Calculator
Find sin, cos, tan, csc, sec, and cot for any angle in degrees or radians. Results shown with full formulas and undefined-value warnings. Free trig calculator, no sign-up needed.
Unit Circle Calculator
Find the unit circle coordinates for any angle. See (cos θ, sin θ), tan θ, and which quadrant the angle lands in. Common angles reference table included. Free trig tool.
This collection of 7+ free trigonometry calculators covers the core operations covered in a standard trig course — from converting between degrees and radians to solving oblique triangles with the law of sines and cosines. Every calculator shows its work step-by-step so you can follow the method, not just get an answer.
What These Calculators Cover
- Degrees & Radians Converter — convert angles in either direction with the formula shown; includes a reference table of common angles
- Sin / Cos / Tan Calculator — compute all six trigonometric functions (sin, cos, tan, csc, sec, cot) for any angle in degrees or radians
- Right Triangle Calculator — solve a right triangle completely from any two known values (two sides, or one side and one angle)
- Law of Sines Calculator — solve oblique triangles given two angles and a side (AAS/ASA) or two sides and a non-included angle (SSA), including the ambiguous case
- Law of Cosines Calculator — solve oblique triangles given two sides and the included angle (SAS) or all three sides (SSS)
- Unit Circle Calculator — look up exact and decimal trig values for any standard angle, with an interactive unit circle diagram
- Inverse Trig Calculator — find the angle (in degrees and radians) from a known sin, cos, or tan value using arcsin, arccos, or arctan
Why Step-by-Step Matters
Trigonometry builds on itself — a wrong sign in the law of cosines or a missed ambiguous case in the law of sines compounds through every subsequent step. These calculators display the complete solution method alongside the answer, so you can check your own work, spot where a mistake occurred, and understand what to do differently next time.
Degrees vs. Radians
All calculators accept input in either degrees or radians. If you are working from a textbook that uses radians, you do not need to convert first — toggle the unit at the top of each calculator. If you need to convert manually, start with the Degrees & Radians Converter.
Solving Triangles: Which Calculator Do You Need?
| Known information | Calculator to use |
|---|---|
| Two sides of a right triangle | Right Triangle Calculator |
| One side + one angle of a right triangle | Right Triangle Calculator |
| Two angles + one side (AAS or ASA) | Law of Sines Calculator |
| Two sides + non-included angle (SSA) | Law of Sines Calculator |
| Two sides + included angle (SAS) | Law of Cosines Calculator |
| Three sides (SSS) | Law of Cosines Calculator |
Frequently Asked Questions
- When do I use the Law of Sines versus the Law of Cosines?
- Use the Law of Sines when you know two angles and a side, or two sides and a non-included angle. Use the Law of Cosines when you know two sides and the included angle, or all three sides — situations where the Law of Sines doesn't have enough information to start.
- Do these calculators work in both degrees and radians?
- Yes, every calculator on this page lets you choose the input and output unit, so you never need to convert manually first.
- What's the ambiguous case in the Law of Sines?
- When solving with two sides and a non-included angle (SSA), the given information can sometimes match two different valid triangles, one valid triangle, or none at all. The Law of Sines Calculator checks for this automatically and shows both solutions when they exist.