📐 Geometry
Trapezoid Calculator
A trapezoid’s area is the average of its two parallel sides multiplied by the height — which is the same as the midline times the height. That makes the midline a genuinely useful number rather than a curiosity: the shape has exactly the same area as a rectangle of that width.
How it works
Top side (b₁)
Bottom side (b₂)
Height
Left leg
Right leg
Area
Midline
Perimeter
Diagonal 1
Diagonal 2
Frequently asked questions
How do I use the Trapezoid Calculator?
Fill in the fields above — the result recalculates instantly as you type. Everything runs in your browser, so the values you enter are never collected or stored.
Is this calculator free?
Yes. It is completely free, requires no account, and works on phones, tablets and desktops.