Concrete and masonry calculators
Work out how much concrete to order for a slab, or how many blocks and bags of mortar a wall takes. Each calculator shows the formula so you can check it by hand.
Concrete and block quick figures
| Item | Figure | Calculator |
|---|---|---|
| Cubic feet in a cubic yard | 27 | Concrete slab |
| 80 lb bag of concrete mix | 0.60 ft³, 45 bags per yd³ | Concrete slab |
| 60 lb bag of concrete mix | 0.45 ft³, 60 bags per yd³ | Concrete slab |
| Standard 8 × 8 × 16 in blocks | 1.125 per ft² of wall | Concrete block |
| 80 lb bag of mortar mix | About 12 standard blocks | Concrete block |
Building on a gravel base? Size it with the fill dirt calculator or the pea gravel calculator.
Sources
- Bag yields, 0.45 ft³ (60 lb) and 0.60 ft³ (80 lb): Quikrete, Concrete Mix data sheet
- 1.125 standard blocks per square foot: Titan America, Block Estimating Guide
- About 12 blocks per 80 lb bag of mortar mix: Quikrete, Mortar Mix data sheet
Last reviewed November 9, 2026. Found a wrong figure? Tell us.