What does the Trigonometry Calculator do?

Calculate sin, cos, tan and inverse functions in degrees or radians. Includes sec, csc, cot. All calculations are performed in your browser using official UK rates and thresholds.

How accurate are the results?

This calculator uses standard mathematical algorithms and provides results accurate to the precision shown. For very large numbers or high-precision requirements, results are rounded to a reasonable number of decimal places.

Can I use this for schoolwork?

Yes. This calculator is suitable for GCSE, A-level and university-level mathematics. It follows standard mathematical conventions used in UK education.

Trigonometry Calculator

Calculate sin, cos, tan and inverse functions in degrees or radians. Includes sec, csc, cot.

Last updated: April 2026 · Source: BBC Bitesize — Trigonometry

Trigonometric Functions

Angle

Unit

sin(45°)

0.70710678

cos(45°)

0.70710678

tan(45°)

sec

1.4142136

csc

1.4142136

cot

45° = 0.7854 radians

Inverse Functions

Value

asin(0.5)

30°

acos(0.5)

60°

atan(0.5)

26.565051°

Disclaimer

This calculator is provided for informational purposes only and should not be considered as financial or tax advice. All calculations are performed locally in your browser — no personal data is collected or sent to our servers. Rates and thresholds are sourced from HMRC and GOV.UK and are updated for the current tax year. Always verify results with HMRC or consult a qualified professional before making financial decisions.

How It Works

Trigonometry deals with the relationships between angles and sides of triangles. The three primary functions — sine (sin), cosine (cos) and tangent (tan) — relate the angles of a right-angled triangle to the ratios of its sides. This calculator computes all six trig functions and their inverses.

The calculator works in both degrees and radians. It can solve a triangle given three pieces of information (e.g. two sides and an angle, or three sides) using the sine rule, cosine rule and angle sum property. Results include all missing sides and angles.

Example: Right triangle with angle 30° and hypotenuse 10

sin(30°) = 0.5 → opposite = 10 × 0.5 = 5
cos(30°) = 0.866 → adjacent = 10 × 0.866 = 8.66
Third angle: 180° − 90° − 30° = 60°
Sides: 5, 8.66, 10

Source: BBC Bitesize — Trigonometry

Frequently Asked Questions

What does the Trigonometry Calculator do?: Calculate sin, cos, tan and inverse functions in degrees or radians. Includes sec, csc, cot. All calculations are performed in your browser using official UK rates and thresholds.
How accurate are the results?: This calculator uses standard mathematical algorithms and provides results accurate to the precision shown. For very large numbers or high-precision requirements, results are rounded to a reasonable number of decimal places.
Can I use this for schoolwork?: Yes. This calculator is suitable for GCSE, A-level and university-level mathematics. It follows standard mathematical conventions used in UK education.