Self-Leveling Concrete Calculator
A 10 by 20 foot floor at 1/4 inch is 4.17 cubic feet. At 0.50 cubic feet per bag, that is 9 bags.
Last updated . Length and width start in feet. Depth starts in inches. Switch the floor to yards or meters, and the depth to millimeters or centimeters. The yield starts at 0.50 ft³ per bag, a planning assumption. No price.
Enter the floor, the average depth, and the cubic feet per bag from the label. Bags are that volume divided by the yield, rounded up.
Sand-and-cement screed: screed calculator. A structural pour: concrete calculator. A flat slab: concrete slab calculator.
Self-leveling compound
0.50 ft³ per bag is a planning yield so the division can be checked. Read the bag. This is not a brand’s yield, and it is not the 2,400 kg/m³ concrete density. No price.
Results
How the bags are counted
Volume = area × average depth. Bags = that volume ÷ cubic feet per bag, rounded up. The opening floor is 10 by 20 feet, 200.00 ft² and 18.58 m². A quarter inch on that floor is 4.17 ft³ and 0.12 m³. At 0.50 ft³ per bag, 4.17 ÷ 0.50 = 8.33, which rounds up to 9 bags.
0.50 ft³ is a planning yield so the division can be checked. Read the bag and type its number. This is not a brand’s yield, and it is not the 2,400 kg/m³ density used for structural concrete. Screed on this site stays a sand-and-cement mix: a 5 by 4 meter floor at 50 mm and 1:4 is 8 bags of cement and 1.06 cubic meters of sand.
Worked example
Leave every field as it opens: floor 10 ft by 20 ft, average depth 0.25 in, bag yield 0.50 ft³. Area reads 200.00 ft² · 18.58 m². Volume reads 4.17 ft³ · 0.12 m³. Bags read 9.
The same floor at 1/8 inch, and at a 0.45 ft³ yield.
| Depth | Yield | Volume | Bags |
|---|---|---|---|
| 0.25 in | 0.50 ft³ | 4.17 ft³ · 0.12 m³ | 9 |
| 0.125 in | 0.50 ft³ | 2.08 ft³ · 0.06 m³ | 5 |
| 0.25 in | 0.45 ft³ | 4.17 ft³ · 0.12 m³ | 10 |
Frequently asked questions
How many bags of self-leveling concrete for a 10 by 20 floor?
Leave the floor at 10 ft by 20 ft, the depth at 0.25 in, and the yield at 0.50. Area reads 200.00 ft² · 18.58 m². Volume reads 4.17 ft³ · 0.12 m³. Bags read 9. 4.17 ÷ 0.50 = 8.33, which rounds up to 9.
What yield is 0.50 cubic feet?
0.50 ft³ per bag is a planning yield so the division can be checked. Read the bag and type that number. It is not a brand’s yield, and it is not the 2,400 kg/m³ density used for structural concrete on this site.
How many bags at 1/8 inch?
Set the average depth to 0.125 in and leave the yield at 0.50. Volume reads 2.08 ft³ · 0.06 m³. 2.08 ÷ 0.50 = 4.17, so bags read 5. Depth is an average. A floor that is deeper in spots needs the average of those depths, not the shallowest reading.
What if the bag yields 0.45 cubic feet?
Set the depth back to 0.25 in and the yield to 0.45. Volume stays 4.17 ft³ · 0.12 m³. 4.17 ÷ 0.45 = 9.26, so bags read 10. The bag count uses the yield you type.
How is the volume calculated?
Volume = area × average depth. A 10 by 20 floor is 200.00 square feet. A quarter inch is 0.25 ÷ 12 feet, and 200.00 × 0.25 ÷ 12 = 4.166…, which prints as 4.17 ft³. Bags divide that volume by the yield and round up. Switch the floor to meters or the depth to millimeters when the plan is metric.
Is this the same as floor screed?
No. Screed on this site is a sand-and-cement mix. A 5 by 4 meter floor at 50 mm and 1:4 is 8 bags of cement and 1.06 cubic meters of sand, on the screed calculator. This page is a bagged compound, counted from a labeled cubic-foot yield.
Is this a structural slab?
No. A structural pour at 2,400 kg/m³ is the concrete calculator, and a flat slab is the concrete slab calculator. Self-leveling here is a thin average depth of a bagged compound. It does not design the slab under the floor.