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Triangle area calculator

Area of a triangle from base and height, three sides, or two sides and the angle between them.

Related tools

All Geometry tools →
Triangle area calculator (Heron's formula)Compute a triangle's area from the length of its three sides.Equilateral triangle calculatorCompute the area, height and perimeter of an equilateral triangle from its side.Area calculatorCompute the area of a rectangle, square, circle or triangle.Parallelogram area calculatorCompute the area of a parallelogram from its base and height.Cone surface area calculatorCompute the total surface area and slant height of a cone from its radius and height.Trapezoid area calculatorCompute the area of a trapezoid from its two parallel sides and height.Annulus (ring) area calculatorCompute the area of a ring from its outer and inner radius.Circle sector area calculatorCompute the area and arc length of a circle sector from its radius and angle.

The Triangle area calculator turns Base, Height into Area, instantly and for free. For instance, with Base = 10 and Height = 6 it returns Area = 30.

How to use it

  1. Enter your values: Base, Height.
  2. Read the result instantly: Area.

Frequently asked questions

What does the Triangle area calculator actually compute?

It takes Base and Height and derives Area from them. The calculation is live as you type, so the result updates on every change.

What information do I need to provide?

2 values: Base and Height. Nothing else is required — no account, no file upload.

Can you show a worked example?

With Base = 10 and Height = 6, the calculator returns Area = 30. Those figures come from running this exact tool, so you can reproduce them by entering the same values.

What happens if I enter larger values?

It moves a lot. Using Base = 20 and Height = 12 instead, Area goes from 30 to 120 — which is why it is worth testing a few scenarios rather than trusting a single figure.

What does it give for smaller values?

Scaled down to Base = 5 and Height = 3, Area comes out at 7.5. The relationship is worth checking at both ends before you rely on a single result.

When would I actually use this?

Homework and site work alike: how much paint a wall takes, how much water a tank holds, whether a corner is square — and, on the coordinate side, the slope between two points, the distance across a plan, the midpoint of a span.

What is the most common mistake?

Mixing units inside one shape. Entering a length in centimetres and a width in metres gives an area wrong by a factor of a hundred, and the result looks perfectly plausible.

What is the difference between the Triangle area calculator and the Triangle area calculator (Heron's formula)?

Both return Area. What differs is what they ask for: this one wants Base and Height, the Triangle area calculator (Heron's formula) wants Side a and Side b. Use whichever matches the numbers you already have.

Is there a tool for the next step?

Equilateral triangle calculator is the closest one after this: Compute the area, height and perimeter of an equilateral triangle from its side.

What else is worth having open alongside it?

Area calculator and Parallelogram area calculator — they come up in the same task often enough to be worth a second tab.

Further reading

All guides →
How-toHow to Find the Area of a Triangle: Base × Height and Heron's FormulaTwo reliable ways to find a triangle's area: half base times height when you know the height, and Heron's formula when you only know the three sides.How-toCircle: Circumference and AreaCircumference is 2πr, area is πr². Here's how radius, diameter and π fit together, both formulas worked through, and how not to mix them up.ExplainerThe Pythagorean Theorem ExplainedIn a right triangle, a² + b² = c². Here's what the formula means, a worked example, how to find any side, and where it's used in real life.How-toHow to Calculate VolumeVolume is the space inside a shape. Here's how to find it for boxes, cylinders and spheres, and why keeping your units consistent is the whole game.How-toHow to Calculate the Square Metres of a RoomFind a room's area by multiplying length by width. Here's the method for rectangular, L-shaped and round rooms, and why area drives your material orders.How-toHow Many Tiles Do You Need? (Floor and Wall)Estimate tiles from the area to cover and one tile's size, then add for cuts and waste. Here's the method, with an example and the 10% rule.