1. Select your shape
Choose from rectangle, circle, triangle, trapezoid, L-shape, annulus, or wall-and-window layouts to match your project.
Calculator workspace
Enter the base and height of a triangle to calculate its area in square feet instantly.
Use the Triangle Square Foot Calculator to find the area of any triangular space in square feet. Enter the base and height measurements, and get results in square feet, square yards, square meters, and acres. Perfect for measuring triangular lots, gable walls, corner areas, and architectural features.
Choose a specialized calculator for your exact project — rooms, shapes, materials, outdoor areas, and unit conversions.
Triangle square footage is the area of a triangular shape measured in square feet. To calculate triangle square footage, multiply the base by the height and divide by 2: Area = 1/2 x Base x Height. Triangle area calculations are used for gable walls, corner lots, angled landscaping features, and decorative architectural sections.
Getting started
The formula for triangle area is: Area = 1/2 x Base x Height. The base is the bottom side of the triangle. The height is the perpendicular distance from the base to the opposite point. A triangle with a 10-foot base and 6-foot height has an area of 30 square feet.
Choose from rectangle, circle, triangle, trapezoid, L-shape, annulus, or wall-and-window layouts to match your project.
Input dimensions in feet, inches, yards, meters, or centimeters. The Square Foot Calculator converts units automatically.
View results in square feet, square yards, square meters, and acres. Add a material price per unit to estimate total project cost.
Quick reference
Material pricing
Enter the price per square foot of material to estimate total cost. The calculator accepts pricing in square feet, square inches, square yards, or square meters and converts to the correct total based on your area.
There are 2 steps to calculate material cost:
To calculate the volume of bulk materials like mulch or gravel for landscaping, convert area to cubic yards or cubic meters by multiplying the area by the depth of material.
Core formula
Area is the amount of space occupied by a 2-dimensional shape. The shape could be a floor, a wall, a playground, or a field. The simplest formula for area applies to any rectangular shape:
Measure the length and width of the space in feet. Multiply the two values to get the area in square feet. A rectangular room that is 12 feet (3.66 meters) long and 10 feet (3.05 meters) wide has an area of 120 sq ft (11.15 sq m).
Square yardage is area measured in yards, and square meters is area measured in meters. Measure in feet, find the area in square feet, then convert to the unit you need.
For an L-shape room, split the floor into 2 rectangular sections, calculate each area, and add the results. Convert all measurements to the same unit before multiplying, if your dimensions are in different units like inches and feet.
Convert other units of measure to feet with these 4 formulas:
| From | To Feet | Formula |
|---|---|---|
| Inches | Feet | Divide by 12 |
| Yards | Feet | Multiply by 3 |
| Meters | Feet | Multiply by 3.28084 |
| Centimeters | Feet | Divide by 30.48 |
For example, 48 inches ÷ 12 = 4 feet. A measurement of 5 meters × 3.28084 = 16.40 feet. The Square Foot Calculator handles these conversions automatically when you select the input unit.
Unit conversion
Measure your space in inches or centimeters, calculate area in square inches or square centimeters, then convert to any unit you need, including square feet, square yards, square meters, or acres.
| Unit | Square Feet Equivalent |
|---|---|
| 1 sq ft | 144 sq in |
| 1 sq yd | 9 sq ft |
| 1 sq m | 10.764 sq ft |
| 1 acre | 43,560 sq ft |
A 300 sq ft room equals 33.33 sq yd, 27.87 sq m, or 43,200 sq in. The Square Footage Calculator displays all conversions at once so you can compare units for flooring, carpet, or tiling projects without manual math.
Shape formulas
The Square Foot Calculator supports 11 shape formulas for construction, interior design, landscaping, and flooring projects. Each formula below includes a diagram with labeled dimensions.
Using measurements in feet: Area = √[s(s − a)(s − b)(s − c)], where s = (a + b + c) ÷ 2. This is Heron's formula. The 3 sides of the triangle do not need to be the same length. Enter the length of each side in feet and the Square Foot Calculator returns the area in square feet, square yards, and square meters. Use this for corner plots, angled architectural sections, and triangular installation zones.
Using measurements in feet: Area (ft²) = ½ × Base × Height. This formula is simpler than Heron's formula and works when you know the base and the perpendicular height of the triangle. A triangle with a 10-foot (3.05-meter) base and 6-foot (1.83-meter) height has an area of 30 sq ft (2.79 sq m).
Waste factor
Add a 10% surplus to your calculated area to account for material waste during cutting, breakage, and pattern matching. This waste factor applies to flooring, carpet, tiling projects, and landscaping materials.
A room with 200 sq ft of floor area needs 220 sq ft of material: 200 × 1.10 = 220 sq ft. Increase the surplus to 15% (multiply by 1.15) for diagonal flooring installation patterns or complex tiling projects with many cuts. The Square Foot Calculator includes a waste factor field for this calculation.
FAQ
Multiply the base by the height and divide by 2. Area = 1/2 x Base x Height. A triangle with a 12-foot base and 8-foot height has an area of 48 square feet.
Area = 1/2 x Base x Height. The height must be perpendicular to the base. For triangles where you know all three sides, use Heron's formula instead.
The height is the perpendicular distance from the base to the opposite vertex. Measure straight up from the base at a 90-degree angle to the highest point.
Heron's formula calculates triangle area using three side lengths: Area = sqrt[s(s-a)(s-b)(s-c)], where s = (a+b+c)/2. Use this when you know all three sides but not the height.
A triangle with base 20 ft and height 10 ft is 100 square feet (1/2 x 20 x 10 = 100 sq ft).
Yes, gable walls are triangular. Measure the width of the wall (base) and the height from the wall top to the roof peak. The Triangle Square Foot Calculator gives you the gable area.