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Pythagorean Theorem Calculator – Missing Leg
Quick answer
If hypotenuse is 13 and known leg is 5, the missing leg is 12.
Enter your values
Missing leg
12
The one unknown value, solved for from the others you provided.
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See how the result changes
Each table re-runs this calculator with one value changed and everything else left as it is.
Missing leg by hypotenuse
If hypotenuse goes from 13 to 19.5, missing leg changes from 12 to 18.8481 (+57%).
| Hypotenuse | Missing leg |
|---|---|
| 6.5 | 4.1533 |
| 9.75 | 8.3703 |
| 13start | 12 |
| 19.5 | 18.8481 |
| 26 | 25.5147 |
Missing leg by known leg
If known leg goes from 5 to 7.5, missing leg changes from 12 to 10.6184 (−12%).
| Known leg | Missing leg |
|---|---|
| 2.5 | 12.7574 |
| 3.75 | 12.4474 |
| 5start | 12 |
| 7.5 | 10.6184 |
| 10 | 8.3066 |
MATH GUIDE
A quick guide to Pythagorean Missing Leg
Use it to get an accurate missing leg in seconds — free, with no sign-up.
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See your missing leg the moment you enter your numbers.
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How to Use the Pythagorean Missing Leg Calculator
1
Enter Hypotenuse
Provide your hypotenuse.
2
Enter Known leg
Provide your known leg.
3
View Your Results
Get your missing leg instantly, calculated on our server.
What is Pythagorean Missing Leg?
This math tool works out your missing leg instantly, so you don't have to do the math by hand.
“One quick calculation, so you always know your missing leg before you decide.”
What Affects Your Missing leg
Your missing leg depends on the values below.
Hypotenuse
Changing your hypotenuse changes your missing leg.
Known leg
Changing your known leg changes your missing leg.
Example Result
Here's what you can expect from a pythagorean missing leg calculation:
- Hypotenuse
- 13
- Known leg
- 5
- Missing leg
- 12
Frequently Asked Questions
- How does hypotenuse affect missing leg?
- If hypotenuse goes from 13 to 19.5, missing leg changes from 12 to 18.8481 (+57%).
- How does known leg affect missing leg?
- If known leg goes from 5 to 7.5, missing leg changes from 12 to 10.6184 (−12%).
- How to calculate pythagorean missing leg?
- Fill in hypotenuse and known leg in the Pythagorean Theorem Calculator – Missing Leg above and your missing leg is calculated instantly. Change any value to see how the result responds.
- What does an example pythagorean missing leg calculation look like?
- If hypotenuse is 13 and known leg is 5, the missing leg is 12.
- Is this calculator free to use?
- Yes — every calculator on this site is completely free, with no sign-up or account required.
- How accurate is this calculator?
- It uses the standard formula and calculates on our server for every request, so results are precise for the values you enter.
- Is my data saved anywhere?
- No. Nothing you enter is stored or sent anywhere unless you choose to share a link with your values included.
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