Pythagorean Theorem Calculator
How it Works
01Identify the Missing Side
Choose whether you want to find the hypotenuse (c) given legs a and b, or find a missing leg (a or b) given the hypotenuse and the other leg.
02Enter the Known Side Lengths
Input the lengths of the two known sides. The calculator works with any unit — the result is in the same unit you enter.
03Get the Missing Side
The tool computes the missing side using a² + b² = c² for the hypotenuse, or √(c² − a²) and √(c² − b²) for the legs, with decimal precision.
04See the Triangle Visualization
A labeled triangle diagram shows your input sides and the calculated side so you can visually verify the right angle relationship and proportions.
What is a Pythagorean Theorem Calculator?

The calculator is grounded in established mathematical and scientific formulas, presented through a clean, intuitive interface that anyone can use without prior technical knowledge. Simply enter your values, and the tool instantly computes your result — with clear labeling so you always know what each input and output represents. We've also included key formula references, so students and learners can understand the math behind the answer.
Whether you need this tool for a one-time calculation or use it regularly as part of your workflow, it's designed to be reliable, accurate, and completely free. No software to install, no account required, and it works seamlessly on any device — desktop, tablet, or smartphone.
Pro Tip: For more relevant tools in the math and science category, try our Calculate Percentage.
How It Works?
Calculation In Practice
Technical Reference
Key Takeaways
Frequently Asked Questions
What is the ?
The calculator is grounded in established mathematical and scientific formulas, presented through a clean, intuitive interface that anyone can use without prior technical knowledge. Simply enter your values, and the tool instantly computes your result — with clear labeling so you always know what each input and output represents. We've also included key formula references, so students and learners can understand the math behind the answer.
Whether you need this tool for a one-time calculation or use it regularly as part of your workflow, it's designed to be reliable, accurate, and completely free. No software to install, no account required, and it works seamlessly on any device — desktop, tablet, or smartphone.
Pro Tip: For more relevant tools in the math and science category, try our Calculate Percentage.
Who typically uses this tool?
How do I use Pythagorean Theorem Calculator?
Is my data kept private?
How do you calculate the side a or b?
Do I need to install anything?
What is a Pythagorean triple?
What is the Pythagorean Theorem used for?
What is Pythagorean Theorem Calculator?
Does it work on mobile devices?
Can side lengths be decimals?
Can I save or share my results?
Do I need to create an account?
Does the Pythagorean Theorem work for all triangles?
Is Pythagorean Theorem Calculator accurate?
Disclaimer
The results provided by this tool are for informational purposes only and do not constitute medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.