calcs.homes
calcs.homes
Enter the floor area and the average pour depth to estimate the volume and the bags of self-leveling underlayment to mix, with a small waste allowance.
Estimate only — low spots and a deeper feathered edge use more than the average depth implies.
We multiply length, width, and average depth for the volume, add a waste allowance, then divide by the yield of one bag — a 50-lb bag of self-leveling underlayment yields roughly 0.45 cubic feet mixed. The count rounds up, and coverage per bag is shown at the depth you entered so you can sanity-check against the bag's data sheet.
The catch is “average” depth. A floor that dips in the middle needs far more product in the low area than a uniform skim coat, and self-leveler flows to the deep spots first. Measure the worst dip, not just the high point, and mix all your bags for one pour rather than letting an edge set before the next batch reaches it.
A 50-lb bag covers about 45–50 sq ft at 1/8 inch, or roughly 22 sq ft at 1/4 inch. Coverage halves as you double the depth.
Most products go from a feather edge up to about 1 inch in a single lift, and some support deeper fills with added aggregate. Check the specific product's maximum.
Almost always. Bare concrete and wood subfloors need the manufacturer's primer so the leveler bonds and does not flash-dry or pinhole. That is a separate purchase.