How do I convert cubic feet to cubic yards?
Divide by 27. The 308 cu ft in the example above are 11.41 cu yd. To convert the other way, multiply cubic yards by 27, so 1 cu yd is 27 cu ft.
Concrete Yard Calculator: Cubic Yards from Feet and Inches
Turn length, width and thickness into the cubic yards of concrete to order, for one pour or several sections at once. Add a zone for every part of the project (slab, walkway, footing, round piers) and read the total yards with an allowance, plus cubic meters and weight.
1. Material Grade & Project Dimensions
Area: 480.0 sq ft (44.59 m²)Net Vol: 8.89 cu yd (6.80 m³)
Area: 120.0 sq ft (11.15 m²)Net Vol: 1.48 cu yd (1.13 m³)
2. Material Takeoff, Blueprint & Cost
Total Concrete Volume (incl. waste)
11.41 cu yd (8.72 m³)
308.0 cu ft · 45,584 lbs (22.79 US tons)
80-lb Concrete Bags (0.60 ft³)
514 bags
12.2 pallets (@ 42 bags/pallet)
60-lb or 40-lb Bag Option
685 × 60-lb
or 1,027 × 40-lb (0.30 cu ft)
Rebar Grid (#4 @ 18" O.C.)
870 lin ft
44 × 20-ft bars recommended
4" Compacted Gravel Sub-Base
10.50 US tons
Crushed stone base under slab
Cost Break-Even: Ready-Mix Truck vs. 80-lb Bags
Ready-Mix Truck saves $2,012
Ready-Mix Delivery (11.41 cu yd)
$548
514 × 80-lb Pre-Mix Bags
$2,560
Show Step-by-Step Formula & Takeoff Math
Net Area = 600.00 sq ft (55.74 m²)
Net Volume = 280.00 cu ft ÷ 27 = 10.37 cu yd
Total Volume (+10% waste) = 308.00 cu ft = 11.41 cu yd (8.72 m³)
80-lb Bags = ceil(308.00 ÷ 0.60) = 514 bags
From square feet to cubic yards
A cubic yard is 3 ft × 3 ft × 3 ft, which is 27 cubic feet or 0.7646 cubic meters. To get the yards for a slab, multiply length × width × thickness in feet and divide by 27. The calculator does this for every zone and adds the results, so a pour with several parts needs only one total.
Example with two zones: a 24×20 ft garage slab at 6 in (9.78 cu yd with the 10% allowance) plus a 30×4 ft sidewalk at 4 in (1.63 cu yd) gives 11.41 cu yd in total, or 8.72 m³. At 148 lb per cu ft that concrete weighs about 45,584 lb.
Plants sell concrete by the cubic yard and usually add a fee for small loads, which is why the page also shows a price comparison with bags. The calculator applies a $140 fee below 4 cu yd; this example is over that limit.
Cubic yards of concrete per 100 sq ft, by thickness
| Thickness | Area covered by 1 cu yd | Cu yd per 100 sq ft | Cu yd per 100 sq ft with 10% allowance |
|---|---|---|---|
| 3 in | 108.0 sq ft | 0.93 | 1.02 |
| 4 in | 81.0 sq ft | 1.23 | 1.36 |
| 5 in | 64.8 sq ft | 1.54 | 1.70 |
| 6 in | 54.0 sq ft | 1.85 | 2.04 |
| 8 in | 40.5 sq ft | 2.47 | 2.72 |
Frequently Asked Questions & Field Guide
How many square feet does one cubic yard of concrete cover?
One cubic yard covers 108.0 sq ft at 3 in, 81.0 sq ft at 4 in, 54.0 sq ft at 6 in and 40.5 sq ft at 8 in, before any allowance for waste.
How much does a cubic yard of concrete weigh?
At the 148 lb per cu ft used for standard 4,000 PSI concrete, one cubic yard weighs about 3,996 lb, close to 2 US tons. Lightweight structural mix at 115 lb per cu ft weighs 3,105 lb per cubic yard.
How many cubic meters are in a cubic yard?
One cubic yard is 0.7646 m³, so the example above (11.41 cu yd) equals 8.72 m³. The result box shows both units.
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