5 free online calculators with step-by-step solutions
Pick the right tool for your problem — 2D shapes, 3D solids, proofs, or composite figures.
Start with these essential trapezoid calculators calculators
A trapezoid (called a trapezium in UK English) is any quadrilateral with at least one pair of parallel sides — the "bases". Its core formula is the area of a trapezoid: A = ½·(a + b)·h, where a and b are the two parallel sides and h is the perpendicular height between them. The calculators below handle the general trapezoid plus three specialised forms: isosceles (non-parallel sides equal), right (two adjacent right angles), and 3-4-5-style trapezoids defined by side lengths. Each tool also returns the midsegment (the average of the two bases), diagonals (which for an isosceles trapezoid are always equal), and the four interior angles when enough constraints are provided.
This collection has 5 trapezoid calculators: 3 are tagged Most Popular, 1 are supporting tools, and 1 are advanced calculators for derivations and proofs. The most-used tools include Trapezoid Angle Calculator, Isosceles Trapezoid Calculator, Trapezoid Calculator.