SINCOSTAN

Trigonometry Calculators & Tools

Free, practical calculators for angles, triangles, and waves — solve a right triangle, apply the laws of sines and cosines, convert degrees and radians, break down a sine wave, invert a trig ratio, and evaluate the six functions and their identities.

Right Triangle Calculator

Solve a right triangle from any two values — a side and an angle, or two sides — using sine, cosine, tangent, and the Pythagorean theorem. Returns every side, both acute angles, area, and perimeter.

Law of Sines & Cosines Calculator

Solve any triangle from an ASA, AAS, SAS, SSS, or SSA combination. The tool picks the right law automatically and flags the ambiguous SSA case.

Degrees to Radians Converter

Convert an angle between degrees and radians, and read its normalised measure, quadrant, reference angle, and unit-circle coordinates (cos θ, sin θ).

Sine Wave Calculator

Analyse a sinusoid y = A·sin(B(x − C)) + D — get B, frequency, amplitude, period, phase shift, midline, maximum and minimum, and evaluate y at any x.

Inverse Trig Calculator

Find an angle from a ratio with arcsin, arccos, or arctan. Returns the principal value in degrees and radians, with the correct range for each function.

Trig Function & Identity Calculator

Evaluate all six trig functions at any angle in degrees or radians, with undefined values handled cleanly and a live check of the Pythagorean identity.