Calculate the area of a triangle from base and height, three sides, two sides and an included angle, or equilateral side length. Estimate square feet, square inches, square yards, square meters, perimeter, waste, material quantity, and cost.
Base and height mode:
The calculator multiplies base by height, then divides by 2 to estimate triangle area.
Three sides mode:
The calculator uses Heron's formula to estimate the area when all three side lengths are known.
Two sides and angle mode:
The calculator uses two side lengths and the included angle between them to calculate triangle area.
Equilateral mode:
The calculator estimates area, height, and perimeter for a triangle where all three sides are equal.
A triangle area calculator helps estimate triangular spaces for roof gables, land sections, gardens, concrete, flooring, tile, landscaping, walls, and construction planning.
It can help calculate square footage, compare area units, estimate material quantity, add waste, and estimate material cost.
Your result shows the triangle area, perimeter, estimated height, area with extra waste, pieces or units needed, and estimated cost based on the values you enter.
Multiply the triangle base by the triangle height, then divide by 2. For example, a triangle with a 12 foot base and 8 foot height has an area of 48 square feet.
The most common formula is Area = 1/2 × Base × Height.
Use Heron's formula. First find the semi-perimeter, then use √(s(s − a)(s − b)(s − c)) to estimate the area.
Yes. If you know all three sides, use Heron's formula. If you know two sides and the included angle, use 1/2 × a × b × sin(C).
Yes. Triangle layouts often create cuts and offcuts. For flooring, tile, roofing, landscaping fabric, sod, or concrete planning, adding 5% to 15% extra is commonly helpful.