Right triangle calculator
Enter the two perpendicular sides to find the hypotenuse, area, perimeter and acute angles. Use it to check a drawing or compare diagonal lengths; the angle opposite each entered side is labeled separately.
Free to use. No email or account required.
Your inputs
The editable example is illustrative. Enter your own dimensions, operating data, prices, and fees. Results update as you edit.
Calculations run in your browser. Inputs are not saved or sent to analytics.
How it works
- Hypotenuse = √(² + ²)
- Area = × ÷ 2
- Worked example
- 3² + 4² = 5²; 3 × 4 ÷ 2 = 6 m²
Input and formula key
Your result
Complete the inputs to see your result.
Assumptions and limitations
Both lengths must be positive and perpendicular. Inputs and length outputs use metres; area uses square metres and angles use degrees. The triangle is flat and exact; measurement uncertainty and construction tolerances are not modeled.
Sources
- OpenStax — mathematical formulas Sources reviewed: 2026-10-28
Processing and privacy
The calculation or transformation runs in your browser. The tool does not send its input values or generated output to an application server. Loading a page still makes infrastructure requests; optional analytics and Google consent messages have separate controls.
Privacy Policy. Privacy & preferences in the footer controls optional analytics.
Sources and maintenance
Maintained by emonster. Sources are listed with their own review dates; these are not live-data timestamps or claims of independent expert certification.
