Self leveler calculator: bags by depth
Every 50 lb bag of self-leveling underlayment makes about 0.5 cubic feet of material. Spread over a floor, that's:
| Average depth | Sq ft per 50 lb bag | 100 sq ft floor | 12 × 12 ft floor |
|---|---|---|---|
| 1/8 in | 48 | 3 bags | 4 bags |
| 1/4 in | 24 | 5 bags | 7 bags |
| 3/8 in | 16 | 7 bags | 10 bags |
| 1/2 in | 12 | 10 bags | 14 bags |
| 3/4 in | 8 | 14 bags | 20 bags |
| 1 in | 6 | 19 bags | 27 bags |
Bag counts include 10% extra. CUSTOM rates its LevelQuik RS at 46–48 sq ft per bag at 1/8 in, which matches the half-cubic-foot yield MAPEI publishes for Ultraplan Easy — so these numbers hold across the common brands.
How deep will the pour be?
Average depth is the number people get wrong. A floor is rarely uniformly low: it dips at one end or sags between joists. Switch Depth to Shallowest & deepest, enter both, and the calculator averages them — while holding at least 1/8 in over the high spots, because a feather-thin skim cracks.
To find the low spots, lay a 6 or 8 ft straightedge across the floor in several directions and measure the gaps under it. Vinyl plank makers such as COREtec want the subfloor flat within 3/16 in over 10 ft, and large-format tile is stricter still, so that's the minimum target for most pours.
Before you pour
- Prime. Every brand requires its own primer on concrete and plywood. It stops the subfloor from sucking water out of the mix, which causes pinholes and weak bond.
- Dam the edges. Foam backer rod or weatherstrip along doorways and at the bottom of walls keeps the leveler where it belongs. On a wood subfloor, follow the maker's rules for metal lath and minimum thickness.
- Mix exact water. Too much water makes the surface weak and dusty. Mix one bag at a time with a paddle on a 1/2 in drill, and have a helper mixing the next bag while you pour.
- Pour continuously. Most levelers flow for 10 to 15 minutes. Work away from the door in ribbons and keep a wet edge.
Once it's cured, the tile calculator or the flooring calculator sizes the finish floor. Still choosing the floor? Our LVP vs laminate comparison covers water, wear and price. Coating a garage slab instead of covering it? Use the epoxy floor calculator.
