Calculators · Self Leveling Concrete Calculator
Concrete & MasonrySelf Leveling Concrete Calculator
Enter the floor area and the thickness, pick a product and get the bags to buy. The coverage comes from the manufacturers’ data sheets.
Self leveling compound needed
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How to calculate how much self leveling concrete you need
Self leveling compound is sold by the bag, and each bag covers a different area depending on how thick you pour it. The manufacturers publish the coverage of a bag at a given thickness, so the calculation starts there.
| Step | Formula |
|---|---|
| 1. Floor area | length (ft) × width (ft) |
| 2. Coverage at 1/4 inch | coverage on the bag × (thickness it refers to ÷ 0.25) |
| 3. Bags | area × thickness (in) ÷ (0.25 × coverage at 1/4 inch) |
| 4. Bags with extra | bags × (1 + extra ÷ 100), rounded up |
Coverage changes in inverse proportion to the thickness. The CustomTech chart shows it: 23 to 24 square feet per bag at 1/4 inch and 11.5 to 12 at 1/2 inch. When the manufacturer gives a range, the result uses the lower figure, which means more bags, and the breakdown shows how many bags the upper figure would need. For a round area, pick “Circle” and type the diameter. The calculator also reads measurements typed like 10'6" or 10 ft 6 in.
Example: a 12 ft by 15 ft room
A room measures 12 ft by 15 ft and the floor needs 1/4 inch on average. You choose the QUIKRETE Self-Leveling Floor Resurfacer, whose data sheet gives 21 square feet per 50 lb bag at 1/4 inch, and you add 10% extra.
| Step | Operation | Result |
|---|---|---|
| Floor area | 12 × 15 | 180 ft² |
| Bags | 180 × 0.25 × 4 ÷ 21 | 8.57 bags |
| With 10% extra | 8.57 × 1.10 | 9.43 bags |
| Bags to buy | 9.43 rounded up | 10 bags |
| Weight | 10 × 50 lb | 500 lb |
The same room with the CustomTech TechLevel XP-1 (23 to 24 square feet per bag at 1/4 inch) and 10% extra needs 8.6 bags with the lower figure and 8.25 with the upper one. Both round up to 9 bags.
How much does a bag of self leveling concrete cover?
The table copies the coverage published by five manufacturers, in square feet per bag, as each data sheet gives it. They were checked in October 2026. A dash means the sheet does not give that thickness. CustomTech says its chart is for estimating and TEC says its coverages are approximate. The Sika sheet adds that its figures do not include allowance for surface profile, porosity or waste.
| Product (bag size) | 1/8 in | 1/4 in | 1/2 in | 1 in |
|---|---|---|---|---|
| QUIKRETE Self-Leveling Floor Resurfacer (50 lb) | — | 21 | — | — |
| SikaLevel (50 lb) | 42 | 21 | 11 | 5.3 |
| CustomTech TechLevel XP-1 (50 lb) | 46 to 48 | 23 to 24 | 11.5 to 12 | 5.75 to 6 |
| Fortane SL-1C by TEC (50 lb) | 42 to 48 | 21 to 24 | 10 to 12 | 5 to 6 |
| HENRY 544 Floor Leveler (40 lb) | 40 | 20 | — | — |
The calculator fills in the figure at 1/4 inch for each product. For a thickness the sheet does not list, it scales that figure in proportion to the thickness, which is how the published tables behave. QUIKRETE also states that one 50 lb bag gives 0.45 cubic feet of material at a pourable consistency. The Henry bag weighs 40 lb and the others weigh 50 lb, so compare bags and not only square feet.
Bags needed for 100 square feet
Bags to buy for 100 square feet, rounded up, using the lower coverage figure of each product and no extra. Multiply by your area ÷ 100 for a larger floor.
| Product | 1/8 in | 1/4 in | 1/2 in |
|---|---|---|---|
| QUIKRETE Self-Leveling Floor Resurfacer | 3 | 5 | 10 |
| SikaLevel | 3 | 5 | 10 |
| CustomTech TechLevel XP-1 | 3 | 5 | 9 |
| Fortane SL-1C | 3 | 5 | 10 |
| HENRY 544 Floor Leveler (40 lb bags) | 3 | 5 | 10 |
Tips for ordering
- Measure the floor in sections and give each one its own average thickness. A floor with deep low spots needs more than a flat one.
- Read the minimum and maximum thickness on the data sheet of your product. The calculator warns you when a thickness is outside 1/8 to 2 inches, the range of the longest tables we checked.
- Use the extra box for the allowance your installer or the manufacturer recommends. It is added before the bags are rounded up.
- Check the bag weight. Some products come in 40 lb bags and some in 50 lb bags.
- For a regular concrete slab, use the concrete calculator. To turn a volume into cubic yards, use the cubic yard calculator.
Frequently asked questions
How many bags of self leveling concrete do I need?
Multiply the floor area in square feet by the thickness in inches, then divide by one quarter of the coverage of one bag at 1/4 inch. A 12 ft by 15 ft room at 1/4 inch with a bag that covers 21 square feet at that thickness needs 180 × 0.25 × 4 ÷ 21 = 8.57 bags, so 9 bags. Add your extra on top before you round up.
How much does a bag of self leveling concrete cover?
It depends on the product and the thickness. The 50 lb bag data sheets we checked in October 2026 give 21 to 24 square feet at 1/4 inch and 42 to 48 square feet at 1/8 inch. Coverage doubles when the thickness is cut in half. Take the figure from the bag you are buying.
How deep does self leveling concrete need to be?
Each product has its own minimum and maximum thickness, so read the data sheet of the one you buy. The coverage tables of the CustomTech, TEC and Sika products we checked start at 1/8 inch and go up to 1 or 2 inches. QUIKRETE says to place it up to 5/8 in thick, in layers of no more than 5/8 in for deeper areas, priming between layers. Type your thickness into the calculator in inches or in any other unit.
How much extra self leveling concrete should I buy?
The Sika data sheet says its coverage figures do not include an allowance for surface profile, porosity or material waste. How much to add depends on your floor and the product, so ask the manufacturer or your installer. Enter that percentage in the extra box and the calculator adds it before it rounds up the bags. Leave it empty to add nothing.
How do I calculate a floor with low spots?
Add one area for each section and give each one its own average thickness. A large flat zone at 1/8 inch and a dip at 1/2 inch are two areas. The calculator adds the bags of every area and shows the average thickness of the whole floor.
How much does self leveling concrete cost per square foot?
Prices change by region and brand, so this calculator does not show them. Take the number of bags from the result and ask local suppliers for a quote per bag. Dividing that quote by the square feet in the result gives your cost per square foot.
How many bags of regular concrete do I need?
Regular concrete is sold in bags that yield a fixed volume, and this calculator is for leveling compounds sold by coverage. For a slab or a footing, use the concrete calculator. For a volume in cubic yards, use the cubic yard calculator.
More calculators
- Concrete Calculator Find how many cubic yards of concrete or how many bags you need for a slab, footing, wall or column.
- Square Footage Calculator Add rooms, circles or triangles and get the total in sq ft, sq yd, m² and acres.
- Tile Calculator Count the tiles and boxes for a floor or wall, with grout joints and waste.