How it works
Calculate area from two parallel bases and the perpendicular distance between them. Sloping side lengths are unnecessary.
A = (a+b)h/2
Worked example
Show example inputs and result
First parallel base: 8 · Second parallel base: 4 · Perpendicular height: 3.
- Area
- 18
Questions and answers
Why are some results rounded?
Results display up to 8 decimal places. Calculations use the unrounded values; very small values use scientific notation. JavaScript floating-point arithmetic can introduce tiny rounding differences.
Are my inputs sent to a server?
The calculator processes inputs in your browser. Its code does not send your values to a server.
Method reviewed: October 8, 2026 · Methods & accuracy