How much fill dirt for a 20×30 pad

Worked example: cubic yards, tons, and truckloads of fill dirt for a 20×30 ft pad at common depths.

Short answer: a 20×30 ft pad at 6 inches deep is about 11.1 cubic yards raw. With a 12% buffer ≈ 12.4 yd³ — roughly 15.5 tons of fill dirt at 1.25 t/yd³, or about one tandem dump (14 yd³ box) if volume-limited.

At other depths

4 in: ~7.4 yd³ raw → ~8.3 yd³ with 12% buffer
6 in: ~11.1 yd³ raw → ~12.4 yd³ with 12% buffer
8 in: ~14.8 yd³ raw → ~16.6 yd³ with 12% buffer (often into tri-axle / second load territory)

Dense or wet fill may be weight-limited before the truck box is full — confirm with your hauler.

Run your pad in the calculator About the buffer

FAQ

Is 6 inches the right depth?

It depends on the pad design and local practice. Use the depth your engineer, inspector, or builder specifies.

Can I use topsoil instead of fill dirt?

Usually not for structural pads. Topsoil is a finish material; fill dirt is for building grade. Use the matching calculator for each layer.