Sources for Our Concrete Numbers
Every outside fact on this site comes from one of the sources below; values this site sets itself are labelled as this calculator's own rule.
Source List
| Organization | Document | Used for |
|---|---|---|
| Quikrete | Concrete calculator, product pages 1101 and 1004, Portland cement page | bag yields, pallets, 4,000 psi, post hole rule, 1:2:3 mix |
| Oldcastle APG (Sakrete) | Sakrete High-Strength and Maximizer listings; Sakrete setting posts and estimating guides | Sakrete yield and strength, post depth, gravel, dry pour |
| NRMCA | Concrete in Practice 8, 11 and 31 | order 4–10% extra, curing, truck size, water |
| ICC | 2021 International Residential Code (R311.7, R402.2, R403.1.1, R404.1.2, R506) | minimum slab and footing size, stairs, strength, reinforcement |
| NIST | SP 811 Appendix B.9 | unit conversions |
| FHWA | Lightweight concrete primer | concrete density, steel allowance |
| Concrete Network | Concrete prices; driveway thickness | price ranges, driveway thickness |
| Sonoco | Sonotube Builder's Tube brochure | tube diameters and lengths |
| Bullfrog Spas | Hot tub foundation guide | hot tub pad thickness |
| University of Illinois | Concrete: The Basic Mix | 1:2:3 mix, water, volume vs weight |
Last reviewed 2026-11-05. Numbers come from our tested engine; see how we calculate and our sources.