Concrete Bag Calculator — ft, bags, cost comparison
How to use this calculator
Choose how to enter your volume: type in cubic yards or cubic feet directly, or enter length × width × depth dimensions. The calculator shows a side-by-side comparison of all common bag sizes so you can pick the most economical option.
Direct volume — enter yd³ or ft³ if you already know the volume.
Dimensions — enter L × W × D in feet and inches for automatic volume calculation.
Waste — always add 10–15% for spillage and over-excavation.
| Bag Size | Yield | Bags | Weight | Cost |
|---|---|---|---|---|
| 40 lb | 0.30 ft³ | — | — | — |
| 50 lb | 0.375 ft³ | — | — | — |
| 60 lb | 0.45 ft³ | — | — | — |
| 80 lb | 0.60 ft³ | — | — | — |
| 90 lb | 0.675 ft³ | — | — | — |
Saved Calculations
| Time | Volume | 40 lb | 60 lb | 80 lb | Best Cost |
|---|
How Many Bags of Concrete Do I Need?
This concrete bag calculator helps you determine the exact number of premixed concrete bags for any project. Enter your volume directly in cubic yards or cubic feet, or input length × width × depth dimensions. The calculator compares all common bag sizes (40, 50, 60, 80, and 90 lb) side by side.
Bag Yield Reference
Approximate yield per bag of premixed concrete (Quikrete, Sakrete, etc.):
40 lb = 0.30 ft³ (0.011 yd³) · 50 lb = 0.375 ft³ (0.014 yd³) · 60 lb = 0.45 ft³ (0.017 yd³) · 80 lb = 0.60 ft³ (0.022 yd³) · 90 lb = 0.675 ft³ (0.025 yd³)
Formula
Volume: L (ft) × W (ft) × D (ft) = ft³. Divide by 27 for yd³.
Bags: ⌈volume (ft³) / yield per bag⌉ × (1 + waste%)
FAQ
Which bag size is best? 80 lb bags are the most popular for medium projects — best balance of yield and handling weight. Use 40–60 lb bags for small repairs or if you have back concerns. 90 lb bags for large volumes.
How many 80 lb bags per yard? Approximately 45 bags of 80 lb concrete per cubic yard (27 ft³ / 0.6 ft³ per bag = 45).
