Trigonometry Calculators

Solve right and oblique triangles, evaluate trigonometric functions, and convert between degrees and radians.

About trigonometry calculators

Trigonometry calculators handle the six trigonometric functions (sine, cosine, tangent, cosecant, secant, cotangent) plus their inverses, and their application to right and oblique triangles. Fundamental calculations include function evaluation at any angle (in degrees or radians), inverse trig functions returning angles from ratios, and the law of sines and law of cosines for solving oblique triangles.

Right-triangle solvers use the classic mnemonic SOH-CAH-TOA (sin = opposite/hypotenuse, cos = adjacent/hypotenuse, tan = opposite/adjacent) with automatic Pythagorean theorem completion when the two shorter sides are known. Given any two of the three sides, or any one side plus either non-right angle, the calculator returns all remaining sides and angles.

Oblique triangles (no right angle) require the law of sines (a/sin A = b/sin B = c/sin C) or law of cosines (a² = b² + c² − 2bc cos A). The calculator selects the appropriate method based on which quantities are provided. The ambiguous SSA case where the given side opposite the given angle is shorter than the other given side but longer than the height can produce zero, one, or two valid triangles — the calculator returns both solutions when both exist.

Angle unit conversion between degrees, radians, and gradians uses the exact factors: 180 degrees = π radians, 1 gradian = 0.9 degrees. Function values at special angles (0°, 30°, 45°, 60°, 90° and their multiples) return exact values in radical form where appropriate (sin 30° = 1/2 exactly, sin 45° = √2/2 exactly).

Applications include physics (projectile motion, wave equations, oscillations), engineering (structural analysis, surveying, signal processing), navigation (great-circle distance, bearing calculations), astronomy (celestial coordinate conversions), and computer graphics (rotation matrices, 3D transformations). Every calculator page shows the underlying formula and identifies which trigonometric identity was used.

Reviewed by the ScoutMyTool editorial team. Formulas verified against primary authoritative sources.

All tools

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Sine Calculator
Compute sin(x) for any angle in degrees or radians.
Cosine Calculator
Compute cos(x) for any angle.
Tangent Calculator
tan(x) = sin(x) / cos(x). Undefined where cos(x) = 0 (at 90°, 270°, …).
Arcsine Calculator
sin⁻¹(x) — find the angle whose sine is x. Domain [-1, 1], range [−90°, 90°].
Arccosine Calculator
cos⁻¹(x) — find the angle whose cosine is x. Range [0°, 180°].
Arctangent Calculator
tan⁻¹(x) — find the angle whose tangent is x. Range (−90°, 90°).
Degrees to Radians Converter
Convert any angle in degrees to radians. radians = degrees × π/180.
Radians to Degrees Converter
Convert any angle in radians to degrees. degrees = radians × 180/π.
Law of Sines Calculator
a/sin(A) = b/sin(B) = c/sin(C). Solve any triangle given AAS / ASA / SSA.
Law of Cosines Calculator
c² = a² + b² − 2ab·cos(C). Solve any triangle given SAS or SSS.
Right Triangle Solver
Given any 2 of (a, b, c, angle), solve all remaining sides + angles.
Unit Circle Calculator
Angle θ → (cos θ, sin θ) coordinates on the unit circle. Reference angle + quadrant.
Hyperbolic Sine Calculator (sinh)
sinh(x) = (eˣ − e⁻ˣ) / 2. Hyperbolic counterpart of sin.
Hyperbolic Cosine Calculator (cosh)
cosh(x) = (eˣ + e⁻ˣ) / 2. Catenary curve: y = a · cosh(x/a).
Hyperbolic Tangent Calculator (tanh)
tanh(x) = sinh(x) / cosh(x). Bounded between −1 and 1. Used in neural networks.
Angle of Elevation / Depression
tan(angle) = opposite / adjacent. Find angle from height + distance.
Distance to Object (Angle + Height)
distance = height / tan(angle). Range from observer to base of object.
Ladder Safe Angle (4:1 Rule)
For every 4 ft of height, base is 1 ft from wall. Angle ≈ 75.5°.
Roof Rafter Length
Rafter² = run² + rise². Pythagorean from pitch + run.
Satellite Dish Pointing (Az/El)
Approximate azimuth + elevation for geostationary satellite (101°W example).
Surveying Triangulation Distance
Given baseline + 2 angles, find unknown distance via law of sines.