Triangle Area Calculator
For any triangle, area is base times height over two. With the same base and height the area is identical no matter how skewed the shape.
Your numbers
Area
48cm²
Formula
Area = Base × Height ÷ 2
Height means the perpendicular distance to the base — using a slanted side instead overstates the area.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| Base (cm)The side you treat as the bottom when finding area. | 12 | 0 and up |
| Height (cm)The perpendicular height from the base — not the slanted side. | 8 | 0 and up |
Step by step
Quick reference table
Results when only Base (cm) changes and everything else stays put.
| Base (cm) | Area (cm²) |
|---|---|
| 6 | 24 |
| 9 | 36 |
| 12 | 48 |
| 18 | 72 |
| 24 | 96 |
What each result means
| Result | At default values |
|---|---|
| Area (cm²)The space a shape covers — length squared. | 48 |
Common mistakes
Height means the perpendicular distance to the base — using a slanted side instead overstates the area.
Glossary
- Base
- The side you treat as the bottom when finding area.
- Height
- The perpendicular height from the base — not the slanted side.
- Area
- The space a shape covers — length squared.
Frequently asked questions
Q. How is Triangle Area Calculator calculated?
Area = Base × Height ÷ 2 — For any triangle, area is base times height over two. With the same base and height the area is identical no matter how skewed the shape.
Q. Can you walk through an example?
With Base 12cm, Height 8cm, the answer is Area 48cm².
Q. What do I need to enter?
Enter Base, Height. The result recalculates as you type, and an empty box counts as zero.
Q. How much does the answer move if I change a number?
Changing only Base (cm) moves the answer to Base (cm) 6 → Area (cm²) 24 and Base (cm) 24 → Area (cm²) 96. The table below lays out five steps.
Q. How are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
Q. Anything to watch out for?
Height means the perpendicular distance to the base — using a slanted side instead overstates the area.
Related calculators
Keep your length units consistent across inputs — mixing centimetres and metres throws results far off.