Everyday Tools

Triangle Area Calculator

Calculate the area of a triangle from base and height.

Updated April 16, 2026
Free online tool
Planning and research use

Why this page exists

Triangle area is easier to check when base and height are turned into one direct answer instead of being worked out longhand each time. This calculator helps visitors calculate triangle area from base and height using standard one-half base-times-height math.

Interactive tool

Run the estimate

Enter your numbers and read the result first, then use the sections below to understand what affects the outcome.

Calculator

Triangle area calculator

Calculate the area of a triangle from its base and height.

Result

48.000000 sq units

Calculated triangle area using one-half of the base multiplied by the height.

Triangle area48.000000 sq units

Base used12.000000 units

Height used8.000000 units

Formula basis used0.5 × base × height

A triangle with a base of 12.000000 units and a height of 8.000000 units has an area near 48.000000 sq units.
The full base-times-height rectangle would be 96.000000 sq units, and the triangle takes half of that area.
Use the result as a quick geometry check for drafting, measurement, and school problems involving triangles.

This is a standard triangle-area estimate. The base and height must use the same unit, and the height should be measured perpendicular to the base.

Planning note

Last updated April 16, 2026. Use this tool to compare scenarios and plan ahead, then confirm important details with the lender, employer, insurer, contractor, or other qualified provider involved in the final decision.

How it works

What the calculator is doing

Enter the triangle base and height using the same unit.

The calculator multiplies base by height and takes half of that amount.

It shows the triangle area and the dimensions used in the calculation.

Understanding your result

This is standard triangle area math. The height should be the perpendicular height to the base, and both measurements should use the same unit.

Browse more everyday tools

Examples

Ways people use this tool

Example scenarios help turn a quick estimate into a more useful comparison or planning step.

Check a homework or worksheet answer

A quick triangle-area result can make it easier to verify geometry work without redoing the whole problem.

Work from measured base and height

This can help with drafting, layout, or simple field-measurement problems where triangle area is needed.

Use it with other geometry tools

Triangle area often fits naturally beside trapezoid-area, surface-area, and distance-formula tools.

FAQ

Common questions

How is triangle area calculated here?

The calculator uses the standard formula 0.5 × base × height.

What height should I use?

Use the perpendicular height to the base, not just the length of another triangle side unless it is the actual altitude.

Why do base and height need the same unit?

Because the area formula multiplies those two measurements directly, so mismatched units would create an inconsistent result.

Related tools

Keep comparing

Use these related tools to compare nearby scenarios, check a second estimate, or keep narrowing down the right decision.

Everyday ToolsUpdated April 13, 2026