Law of Sines Calculator

Solve triangles using the law of sines.

This Law of Sines Calculator allows you to calculate or convert values instantly. It is free, fast, and easy to use.

  • Free Online Tool
  • Instant Results
  • Mobile Friendly
  • No Installation
  • Secure & Private

Understanding This Calculator

Law of Sines Formula

The Law of Sines is an equation relating the lengths of the sides of a triangle to the sines of its angles.

a / sin(A) = b / sin(B) = c / sin(C)

Example 1

Side a = 10, Angle A = 30°, Angle B = 45°

  • 10 / sin(30°) = b / sin(45°)
  • 10 / 0.5 = b / 0.707
  • 20 = b / 0.707
  • b = 20 × 0.707 ≈ 14.14

Example 2

Side a = 7, Angle A = 90°, Angle B = 30°

  • 7 / sin(90°) = b / sin(30°)
  • 7 / 1 = b / 0.5
  • b = 7 × 0.5 = 3.5

How to Use

  • Enter a known side.
  • Enter the angle opposite to it.
  • Enter another angle.

Frequently Asked Questions

How do I use the Law of Sines Calculator?

Enter your values in the input fields, and the result will appear instantly.

Is this calculator free to use?

Yes, this calculator is 100% free and does not require any registration or subscription.

Is it mobile-friendly?

Absolutely! Our tool is optimized for all devices, including mobile phones, tablets, and desktop computers.