Calculate rectangle area.
GeometryOpen
Area of a Triangle Calculator
Quick answer
If base is 10 and height is 6, the area is 30 square units.
Triangle area: Area = ½ × base × height.
Enter your values
Area
30square units
The amount of flat surface this covers, in square units.
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About the Area of a Triangle Calculator
The area of a triangle is half its base multiplied by its height, where the height is the perpendicular distance from the base to the opposite corner. Enter the base and the height.
A triangle with a base of 10 and a height of 6 has an area of 30.
Triangle area
Area = ½ × base × height
Things to keep in mind
- The height must be perpendicular to the base, not the slanted side.
- Use the same unit for base and height.
- A triangle is exactly half of a rectangle with the same base and height.
See how the result changes
Each table re-runs this calculator with one value changed and everything else left as it is.
Area by base
If base goes from 10 to 15, area changes from 30 square units to 45 square units (+50%).
| Base | Area |
|---|---|
| 5 | 15 square units |
| 7.5 | 22.5 square units |
| 10start | 30 square units |
| 15 | 45 square units |
| 20 | 60 square units |
Area by height
If height goes from 6 to 9, area changes from 30 square units to 45 square units (+50%).
| Height | Area |
|---|---|
| 3 | 15 square units |
| 4.5 | 22.5 square units |
| 6start | 30 square units |
| 9 | 45 square units |
| 12 | 60 square units |
MATH GUIDE
A quick guide to Triangle Area
Use it to get an accurate area in seconds — free, with no sign-up.
Instant results
See your area the moment you enter your numbers.
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Every calculator here is free to use, with no account required.
Accurate & transparent
The same standard formula runs on our server for every calculation.
How to Use the Triangle Area Calculator
1
Enter Base
Provide your base.
2
Enter Height
Provide your height.
3
View Your Results
Get your area instantly, calculated on our server.
What is Triangle Area?
This math tool works out your area instantly, so you don't have to do the math by hand.
“One quick calculation, so you always know your area before you decide.”
What Affects Your Area
Your area depends on the values below.
Base
Changing your base changes your area.
Height
Changing your height changes your area.
Example Result
Here's what you can expect from a triangle area calculation:
- Base
- 10
- Height
- 6
- Area
- 30 square units
Frequently Asked Questions
- How does base affect area?
- If base goes from 10 to 15, area changes from 30 square units to 45 square units (+50%).
- How does height affect area?
- If height goes from 6 to 9, area changes from 30 square units to 45 square units (+50%).
- How to calculate triangle area?
- Fill in base and height in the Area of a Triangle Calculator above and your area is calculated instantly. Change any value to see how the result responds.
- What does an example triangle area calculation look like?
- If base is 10 and height is 6, the area is 30 square units.
- 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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