Trapezoid Area Calculator

Area of a four-sided shape with two parallel sides.

How the Math Works

The trapezoid area formula calculates the space inside a four-sided shape with two parallel sides. Here, 'a' and 'b' represent the lengths of these parallel sides (called bases), and 'height' is the perpendicular distance between them. The formula adds the two bases, divides by two to find the average base length, then multiplies by the height - effectively treating the trapezoid as a rectangle with that average base. This works because averaging the bases gives the equivalent single base length that would create the same area when multiplied by the height.

Practical Applications

To use this calculator, simply enter the lengths of your trapezoid's two parallel sides and the perpendicular height between them. For example, if you have a trapezoid-shaped garden bed with one side measuring 10 feet, the opposite side 15 feet, and a perpendicular width of 8 feet, input these values to instantly get the area (100 square feet). This is commonly used in construction for calculating wall areas, in landscaping for irregular plots, and in engineering for cross-sectional measurements of beams or channels.

Day-to-Day Use

You might use this calculation when planning materials for a trapezoidal backyard patio, determining how much paint is needed for a trapezoidal wall section, or figuring out the fabric required for a trapezoidal tablecloth. It's also helpful when comparing sizes of irregularly shaped lots when buying property, or when calculating the amount of mulch needed for a flower bed with tapered edges. The calculator saves time and reduces guesswork in any DIY project involving trapezoidal shapes.

Worked example

a 8, b 5, h 4 → (13/2) × 4 = 26.

FAQ