StructureCalculator

Self-Leveling Concrete Calculator

Floor area
Depth
Product & order
Self-leveling concrete
Bags to buy—
Needed with reserve—
Weight bought—
Left over—
Weight per ft²—
Floor area—
Average depth—
Cost—
Cost per ft²—

Depth check

Estimate from your measurements. The coverage and depth limits on your product's data sheet take priority.

To estimate self-leveling concrete, divide the floor area by the coverage per bag at your depth. Many 50 lb bags cover about 24 ft² at 1/4 in, so a 12 × 10 ft room takes 5 bags, or 6 with a 10% reserve. Enter your room and product below. If you only know the low spots, the calculator can work out the average depth from them.

How far does a 50 lb bag of self-leveling concrete go?

Coverage per 50 lb bag with no reserve, by the product's rated coverage at 1/4 in. The last column is a 120 ft² floor at 24 ft² per bag with a 10% reserve. Your product's chart takes priority.
DepthRated 20 ft²Rated 24 ft²Rated 25 ft²Bags for 120 ft²
1/8 in40 ft²48 ft²50 ft²3
1/4 in20 ft²24 ft²25 ft²6
3/8 in13.3 ft²16 ft²16.7 ft²9
1/2 in10 ft²12 ft²12.5 ft²11
1 in5 ft²6 ft²6.3 ft²22

How to calculate self-leveling concrete

Coverage is published per bag at a stated depth, and it scales with depth. Twice as deep covers half the area, which gives a simple method:

  • Coverage at your depth: coverage at 1/4 in × 0.25 ÷ your average depth in inches.
  • Bags: floor area ÷ coverage at your depth.
  • Reserve: add 5 to 10% and round up to a whole bag.

A 12 × 10 ft room is 120 ft². At 1/4 in with 24 ft² per bag, that's 5 bags, or 250 lb. With a 10% reserve it's 275 lb, or 5.5 bags, so you buy 6.

How much does a 50 lb bag cover?

Plan on 20 to 25 ft² at 1/4 in. TechLevel 100 lists 23 to 24 ft² at 1/4 in, and other common brands work out to 20 to 25 ft². That is about 40 to 50 ft² at 1/8 in and 10 to 12.5 ft² at 1/2 in. The table above shows the full range. Bag sizes and yields vary, so check yours.

How to find the average depth

Depth is the uncertain part, because an uneven floor has no single thickness. To measure it, lay a 6 to 8 ft straightedge across the floor and measure the gap under it at each dip, working in several directions. Then pick the method that fits the floor:

  • Sloped floor: use the deepest and shallowest points mode. It averages the two and adds the layer you want over the high spots.
  • Isolated dips in a flat floor: estimate each dip's area and depth separately. The average of the two extremes would overstate these jobs.

The difference matters. A 120 ft² floor running from 0 to 1/2 in, with 1/8 in over the high spots, averages 3/8 in. That's 9 bags with a 10% reserve. Using 5/8 in across the whole floor would take 14.

Self-leveling concrete or something else?

  • Self-leveling underlayment: the usual product for indoor floors. It's a cement-based floor leveler that goes under tile, vinyl, or laminate, not a finished surface.
  • Depth limits: most products need at least 1/8 in, and TechLevel 100 allows up to 1-1/2 in in one pour. The calculator flags depths outside that range. Your product's limits may be tighter.
  • Deeper fills and new slabs: use the concrete calculator instead. Standard concrete is the better fit for structural work and thick pours.
  • Wood subfloors: these require primer, and many products need extra preparation first. Follow the data sheet.

What it costs to level a floor

Enter your bag price above to get the material cost. Six bags at $40 would be $240, or $2 per ft² at 1/4 in. Add primer, listed at $30 to $50 a gallon. If you hire it out, Inch Calculator puts floor leveling at $3 to $5 per ft².

What the calculator doesn't cover

It sizes the leveler only, not primer, edge strips, or mixing tools. Water per bag and working time depend on the product, so take both from the bag. A German trade guide gives walkable in about 2 to 4 hours, and ready for laminate or vinyl after 24 to 48 hours, as a rough guide. For rooms with many corners, get the area from the square footage calculator and use the known area mode.

Common mistakes

  • Using the 1/8 in coverage for a deeper pour. The big number on the bag is often for the thinnest layer. At 1/4 in it's half that.
  • Using the deepest point as the depth for the whole floor. That can buy far more than you need.
  • Skipping the reserve. The leveler sets quickly, so you can't stop mid-pour for another bag. Have them all on site.
  • Skipping the primer. Primer prevents excess absorption and pinholes.

Coverage, depth limits, and prices come from the guides and product pages listed below, and the examples and table figures were checked with this calculator. Your product's data sheet always takes priority.

Frequently asked questions

How do I calculate self-leveling concrete?

Divide the floor area by the coverage per bag at your depth, then add a reserve. A 120 ft² floor at 1/4 in with 24 ft² per bag takes 5 bags, or 6 with a 10% reserve.

How much does a 50 lb bag of self-leveling concrete cover?

About 20 to 25 ft² at 1/4 in, depending on the product. That is about 40 to 50 ft² at 1/8 in and 10 to 12.5 ft² at 1/2 in. Check the coverage chart for your product.

How many bags do I need for 100 square feet?

About 5 bags at 1/4 in, using 24 ft² per 50 lb bag and a 10% reserve. At 1/8 in you need 3 and at 1/2 in you need 10.

How many bags do I need for 500 square feet?

About 23 bags at 1/4 in, using 24 ft² per 50 lb bag and a 10% reserve. Pours that large usually need a crew and a mixing plan, because the leveler sets quickly.

How thick can self-leveling concrete be poured?

It depends on the product. Most need at least 1/8 in, and TechLevel 100 allows up to 1-1/2 in in one pour. Check the data sheet for your product, since limits differ.

How do I measure how much leveler a floor needs?

Lay a 6 to 8 ft straightedge on the floor and measure the gap at each dip, working in several directions. For a sloped floor, average the deepest and shallowest points and add the layer you want over the high spots.

Do I need primer before self-leveling concrete?

Usually yes. Primer prevents excess absorption and pinholes, and wood subfloors require it. Use the primer your product specifies.

Is self-leveling concrete the same as regular concrete?

No. It is a cement-based underlayment that flows into a flat layer under finished flooring. For slabs, footings, and thick structural pours, use regular concrete.

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