Pre-Calculated Specs for a 20×10 Concrete Slab (4" Depth)
single-car parking pad, long covered breezeway, or elongated patio living area80 lb Bags Needed123 bagsincl. 10% waste
Total Volume2.72 yd³73.3 cu ft
Sub-Base Gravel2.84 yd³~154 bags (50 lb)
#4 Rebar Needed~314 ft18" on-center grid
Expert Contractor Recommendation: With 123 bags (~9,840 lbs of concrete), hand-mixing risks exhaustion and dry "cold joints" between batches. Ordering a ready-mix truck delivery is strongly recommended.
Engineering Considerations for 20×10 Pours
A 20×10 slab covers exactly 200 square feet. This size is commonly used for a single-car parking pad, long covered breezeway, or elongated patio living area. Because this project requires over 1.8 cubic yards (2.72 cu yds), hand mixing is strongly discouraged due to fatigue and cold joint vulnerability. Coordinate with a local ready-mix dispatch supplier.
| Bag Size | Total Bags Needed | Combined Dry Weight | Estimated Material Cost |
|---|---|---|---|
| 80 lb bag | 123 bags | 9,840 lbs (4,463 kg) | $713 - $923 |
| 60 lb bag | 163 bags | 9,780 lbs (4,436 kg) | $799 - $1043 |
| 50 lb bag | 196 bags | 9,800 lbs (4,445 kg) | $833 - $1078 |
| 40 lb bag | 245 bags | 9,800 lbs (4,445 kg) | $882 - $1176 |