MEASURE. ESTIMATE. BUILD.
Find how many cubic yards of concrete a slab or footing needs.
Change any measurement to update your estimate.
Enter dimensions and the tool returns yards to order — ready-mix concrete is sold by the cubic yard.
Ready-mix concrete is ordered by the cubic yard, so this view frames the answer that way. Add 5–10% over your calculated volume — you can't pause a pour to order more without leaving a cold joint.
The single most common ordering error is leaving depth in inches — feet × feet × inches gives a number 12 times too big. Convert depth to feet first, every time. When an area is L-shaped or curved, split it into rectangles you can actually measure and add the volumes; guessing an "average" width on an irregular bed is where orders go wrong.
The math behind the tool:
cubic yards = (length × width × depth, all in feet) ÷ 27Sources: Oregon State University Extension (soil and compost volume guidance).
There are 27 cubic feet in one cubic yard, because a cubic yard is 3 ft × 3 ft × 3 ft.
Multiply length × width × depth in feet, then divide by 27. For depths given in inches, divide the inches by 12 first to convert to feet.