1. Measure parallel sides
Measure both parallel sides (a and b) in feet.
What is trapezoid square footage?
Trapezoid square footage equals one-half times the sum of parallel sides times height. Apply Area = ½ × (a + b) × h in feet. A trapezoid with parallel sides 10 ft and 14 ft (3.05 m and 4.27 m) and height 8 ft (2.44 m) has 96 sq ft (8.92 m²). For a slanted four-sided shape, see the parallelogram calculator.
Getting started
How to Calculate Trapezoid Square Footage
To calculate trapezoid square footage, measure both parallel sides (a and b) and the perpendicular height between them in feet. Apply Area = ½ × (a + b) × h. Useful for irregular plots, sloped retaining walls, and tapered rooms.
2. Measure height
Measure the perpendicular height between the parallel sides in feet.
3. Apply ½ × (a + b) × h
Trapezoid area = ½ × (a + b) × h. A trapezoid with sides 10 and 14 ft and height 8 ft has 96 sq ft.
Quick reference
Reference
1 acre = 43,560 square feet
1 square yard = 9 square feet
1 square meter = 10.764 square feet
1 square inch = 0.00064516 square feet
Material pricing
Calculate Cost of Materials
Trapezoid area times price per unit equals material cost. Apply trapezoid square footage to tapered lots, sloped roof sections, or angled garden beds.
There are 2 steps to calculate material cost:
- Enter the price per square foot of material covering the trapezoid.
- The Square Foot Calculator multiplies trapezoid area by your price for material total.
Trapezoid shapes have angled non-parallel sides. Add 10% extra material for fitting cuts.
FAQ
Frequently Asked Questions
How do I calculate the square footage of a trapezoid?
Add the two parallel sides, divide by 2, then multiply by the height. Area = [(a + b) / 2] x h. A trapezoid with sides 10 ft and 16 ft and height 8 ft = 104 sq ft.
What is a trapezoid?
A trapezoid is a four-sided shape with exactly two parallel sides. The parallel sides are called bases, and the perpendicular distance between them is the height.
How do I measure the height of a trapezoid?
The height is the perpendicular distance between the two parallel sides. Measure straight across at a 90-degree angle from one parallel side to the other.
What is the difference between a trapezoid and a parallelogram?
A trapezoid has exactly two parallel sides, while a parallelogram has two pairs of parallel sides. Both use different area formulas.
Can I use this for irregular lot calculations?
Yes, many property lots are trapezoidal in shape. Measure the two parallel boundaries and the perpendicular distance between them to calculate lot area.
How do I calculate a trapezoid with sides in inches?
Convert inches to feet by dividing by 12, then apply the trapezoid formula. The calculator handles unit conversions automatically.
REFERENCES
Further Reading & References
Trusted external sources and related sections on this site. External links open authoritative references on Wikipedia and government agencies.
Explore this Square Foot Calculator site
Authoritative external references
- WIKITrapezoid — Wikipedia
- WIKIArea — Wikipedia
- WIKIQuadrilateral — Wikipedia