Concrete Calculator

Outdoor Living

Free concrete calculator for DIY patios, walkways, and slabs. Enter length, width, and depth in imperial or metric units to get volume and bag counts for your project.

Unit system

Slab dimensions

Length

Width

Slab depth

4 in for walkways, 4–6 in for patios

Your estimate

Slab area: 100 sq ft
Cubic yards: 1.23 yd³
80 lb bags: 56 bags
Total volume: 33.3 cu ft

How this calculator works

Enter slab length and width (feet or metres).
Enter depth — 10 cm for walkways, 10–15 cm for patios.
Results show cubic yards or cubic metres (for ready-mix delivery) and bag count for small DIY pours.
Always add 5–10% extra for uneven subgrade and spillage on larger pours.

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