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Floor leveler chart
Put your area, coverage per bag and waste allowance in: 400 sq ft at 10% waste needs 17.60 bags exact, order 18.
★ CONSTRUCTION · FLOORING · LEVELER CHART
Floor Leveler Chart: 18 Bags for 400 Sq Ft at 10% Waste
On the defaults — 400 square feet at 10% waste with 25 square feet per bag coverage — you need 440.00 square feet of leveler coverage, 17.60 bags exact, so order 18 bags. This is the FLOOR-LEVELER version — area times waste divided by coverage, with a lookup table for every common area and waste level — the tile-adhesive-chart page is the TILE-ADHESIVE version — the same divide-and-round-up model counted in adhesive bags; the thinset-chart page is the THINSET version — the same model counted in thinset bags; the grout-chart page is the GROUT version — the same model counted in grout bags; and the mortar-chart page is the MORTAR version — the same model counted in mortar bags.
What does 17.60 bags, order 18, mean?
It means that 400 square feet of floor, with a 10% waste allowance, need 440.00 square feet of leveler coverage, and at 25 square feet per bag that is 17.60 bags — seventeen full bags plus six tenths of another — so you order 18. The fraction is the whole story in miniature: a partial bag cannot be bought in the quantity needed, so any fraction, however small, becomes a whole bag, and 17 bags cover only 425 square feet, leaving 15.00 square feet without leveler. The part people get wrong is rounding to the nearest bag instead of up: 17.60 rounded to the nearest is 18 here by luck, but a 17.40-bag job rounded to the nearest is 17, and 17 bags cover only 425 of the 440.00 square feet needed. The other part people get wrong is treating thickness as free: the 25-square-feet figure is the stated coverage basis at 1/8 inch thickness, and a pour twice as thick covers half the area per bag, which doubles the order before waste is even counted.
Three things to check before you trust the number
Is 25 square feet per bag right for your pour? Twenty-five square feet is the figure this page uses, the stated coverage basis of about 25 square feet per bag at 1/8 inch thickness. Thicker pours and deeper dips eat more compound and cover fewer feet, so the same 400 square feet at 30 square feet per bag would need 14.67 bags, order 15, not 18 — pour depth changes the count completely, even though the area and waste are unchanged. Check your compound maker’s coverage table for your pour depth and substrate, and enter that figure rather than trusting the default for a different thickness.
Did you measure every area? The area entered here must be the total of all floors to be levelled, not the largest single room: a home with 400 square feet downstairs plus halls and bathrooms has more than 400 square feet to level. The 200-square-foot branch needs 8.80 bags, order 9, against the 17.60-bag headline, so missing one room understates the order by whole bags on a bigger job. Measure every area, add them before dividing, and do not subtract small gaps unless your compound maker says to.
Are you counting waste, or a second pour? This page adds 10% for waste — spillage, over-pour and feathering at edges and drains — and that is not a second pour. A second pour doubles the area first: 400 square feet twice-levelled is 800 square feet before waste, which is 880.00 square feet with waste and 35.20 bags, order 36. Treating a second pour as waste, or waste as a second pour, misstates the order by whole bags either way, so decide the pours first and let the waste percentage stay at waste.
Worked example
On the defaults: 400 square feet, 25 square feet per bag, 10% waste.
- Needed area: 400 × 1.10 is 440.00 square feet.
- Exact bags: 440.00 ÷ 25 is 17.60 bags.
- Order: 17.60 rounded up is 18 bags — the fraction becomes a whole bag, because a partial bag cannot be bought.
- Check: 18 bags cover 450 square feet, more than the 440.00 needed; 17 bags cover only 425, which is not enough.
And the other way: the area behind 17.60 bags is 400 square feet, the coverage behind 17.60 bags is 25 square feet per bag, and the waste behind 17.60 bags is 10%. A job of 25 square feet at 0% waste orders exactly 1 bag, and a 1,000-square-foot job at 25 square feet per bag and 0% waste lands exactly on 40.00 bags, order 40.
Every branch, checked
- 200 square feet, 25 square feet per bag, 10% waste: 200 square feet, 25 square feet per bag, 10% waste: 8.80 bags exact — order 9 bags.
- 800 square feet, 25 square feet per bag, 10% waste: 800 square feet, 25 square feet per bag, 10% waste: 35.20 bags exact — order 36 bags.
- 400 square feet, 30 square feet per bag, 10% waste: 400 square feet, 30 square feet per bag, 10% waste: 14.67 bags exact — order 15 bags.
- 400 square feet, 25 square feet per bag, 20% waste: 400 square feet, 25 square feet per bag, 20% waste: 19.20 bags exact — order 20 bags.
The reverses, worked backwards
- Area behind 17.60 bags: 400 sq ft — at 400 sq ft the figures are 17.60 bags exact — order 18 bags.; at the lower neighbor the figures are 15.40 bags exact — order 16 bags.; at the upper neighbor the figures are 19.80 bags exact — order 20 bags..
- Coverage behind 17.60 bags: 25 sq ft per bag — at 25 sq ft per bag the figures are 17.60 bags exact — order 18 bags.; at the lower neighbor the figures are 22.00 bags exact — order 22 bags.; at the upper neighbor the figures are 14.67 bags exact — order 15 bags..
- Waste behind 17.60 bags: 10% waste — at 10% waste the figures are 17.60 bags exact — order 18 bags.; at the lower neighbor the figures are 16.80 bags exact — order 17 bags.; at the upper neighbor the figures are 18.40 bags exact — order 19 bags..
What the defaults assume
The defaults are 400 square feet, 25 square feet per bag and 10% waste, so the headline is one pour of self-leveling compound over a medium floor at 1/8 inch thickness. The model is a multiplication, a division and a ceiling: needed area is area times one plus the waste percentage, exact bags are needed area divided by coverage per bag, and the order rounds exact bags up to the next whole bag, with a 1e-12 epsilon so an exact whole number orders exactly that many. Bag coverage differs by pour depth — the 25-square-feet figure is the stated basis at 1/8 inch, and a thicker pour covers fewer feet, so enter the coverage for the bag and pour depth you will actually use. The area reverse is checked at 50 square feet either side, because 50 square feet at 10% waste is 55 square feet, exactly 2.20 bags; the coverage reverse is checked at 5 square feet either side, because 440.00 over 20 is 22.00 bags and over 30 is 14.67; the waste reverse is checked at 5% either side, because 5% of 400 is 20 square feet, exactly 0.80 bags. The model does not include second pours, primer, tile itself, grout, backer board, fasteners, or tools — count those separately.
Lookup table: bags by area and waste
Each row already includes its waste allowance at 25 square feet per bag: needed area is the area times one plus the waste percentage, exact bags are needed area divided by 25, and the order column rounds up. A row that lands exactly on a whole number orders exactly that many — no extra bag is added for an exact fit. For a different bag coverage, enter your own figure in the calculator above: a thicker pour covers fewer feet, so the order rises.
| Area | Waste | Needed area | Exact bags | Order |
|---|---|---|---|---|
| 100 sq ft | 0% | 100.00 sq ft | 4.00 | 4 bags |
| 100 sq ft | 5% | 105.00 sq ft | 4.20 | 5 bags |
| 100 sq ft | 10% | 110.00 sq ft | 4.40 | 5 bags |
| 100 sq ft | 15% | 115.00 sq ft | 4.60 | 5 bags |
| 200 sq ft | 0% | 200.00 sq ft | 8.00 | 8 bags |
| 200 sq ft | 5% | 210.00 sq ft | 8.40 | 9 bags |
| 200 sq ft | 10% | 220.00 sq ft | 8.80 | 9 bags |
| 200 sq ft | 15% | 230.00 sq ft | 9.20 | 10 bags |
| 400 sq ft | 0% | 400.00 sq ft | 16.00 | 16 bags |
| 400 sq ft | 5% | 420.00 sq ft | 16.80 | 17 bags |
| 400 sq ft | 10% | 440.00 sq ft | 17.60 | 18 bags |
| 400 sq ft | 15% | 460.00 sq ft | 18.40 | 19 bags |
| 800 sq ft | 0% | 800.00 sq ft | 32.00 | 32 bags |
| 800 sq ft | 5% | 840.00 sq ft | 33.60 | 34 bags |
| 800 sq ft | 10% | 880.00 sq ft | 35.20 | 36 bags |
| 800 sq ft | 15% | 920.00 sq ft | 36.80 | 37 bags |
Output · formula · meaning
| Output | Formula | What it means |
|---|---|---|
| Needed area | area × (1 + waste ÷ 100) | 440.00 sq ft — 400 × 1.10. |
| Exact bags | needed area ÷ coverage per bag | 17.60 bags — 440.00 ÷ 25. |
| Order | exact bags rounded up | 18 bags — 17.60 rounds up to the next whole bag. |
| Area behind a target exact figure | exact bags × coverage per bag ÷ (1 + waste ÷ 100) | 400 sq ft — 17.60 × 25 ÷ 1.10. |
| Coverage behind a target exact figure | needed area ÷ exact bags | 25 sq ft per bag — 440.00 ÷ 17.60. |
| Square feet covered by the order | order × coverage per bag | 450 sq ft — 18 × 25, more than the 440.00 needed. |
| Square feet short on one fewer bag | needed area − (order − 1) × coverage per bag | 15.00 sq ft — 440.00 − 17 × 25, which is why rounding down fails. |
| 200 square feet, 25 square feet per bag, 10% waste | same model | 8.80 bags exact — order 9 bags. |
| 800 square feet, 25 square feet per bag, 10% waste | same model | 35.20 bags exact — order 36 bags. |
| 400 square feet, 30 square feet per bag, 10% waste | same model | 14.67 bags exact — order 15 bags. |
| 400 square feet, 25 square feet per bag, 20% waste | same model | 19.20 bags exact — order 20 bags. |
| Area behind 17.60 bags | reverse | 400 sq ft: 17.60 bags exact — order 18 bags. |
| Coverage behind 17.60 bags | reverse | 25 sq ft per bag: 17.60 bags exact — order 18 bags. |
| Waste behind 17.60 bags | reverse | 10% waste: 17.60 bags exact — order 18 bags. |
| 0 square feet | same model | 0.00 bags exact — order 0 bags. |
| Negative area | same model | Area — 0 or more. |
| Zero coverage | same model | Coverage — more than 0. |
| 25 square feet, 0% waste | same model | 1.00 bags exact — order 1 bag. |
Who uses this
- A DIYer levelling a new floor — 400 square feet at 10% waste is 18 bags, with the lookup table covering every other area and waste level without re-measuring.
- A flooring installer ordering for a job — the branches show how the order moves with area, coverage and waste, so a thicker pour is repriced before ordering.
- A homeowner comparing pour depths — the 30-square-feet branch shows what a thinner pour really saves in bags, before the job starts.
- An estimator checking a quote — the reverses recover the area, coverage or waste behind any quoted bag count, which checks a quote without re-measuring the job.
Accuracy & limitations
Figures are the model’s own arithmetic on the numbers you type, computed from unrounded values and displayed rounded HALF_UP to 2dp, with orders rounded up using a 1e-12 epsilon so exact fits are not over-ordered. The main limitation is the coverage figure, not the arithmetic: bag coverage varies widely with pour depth and substrate — a thick pour over deep dips eats far more compound than a thin skim over a flat floor — so check your compound maker’s coverage table for your pour depth and enter your own figure when your pour differs. The 25-square-feet figure is the stated coverage basis at 1/8 inch thickness, not a universal guarantee for every product or pour. This page is a calculation tool, not trade advice — follow the compound maker’s instructions for priming, mixing, working time and curing.
Cite this calculator
400 square feet at 10% waste with 25 square feet per bag coverage needs 440.00 square feet, 17.60 bags exact: order 18 bags. Source: Bright Side Kit, https://brightoolbox.com/floor-leveler-chart/, accessed 29 October 2026.
Frequently asked questions
How many square feet does one bag of floor leveler cover?
This page uses 25 square feet per bag, the stated coverage basis of about 25 square feet per bag at 1/8 inch thickness. A thicker pour covers fewer feet, so the same 400 square feet at 30 square feet per bag needs 14.67 bags, order 15 — the calculator divides by whatever you enter, so the answer stays honest for your pour depth.
Is floor leveler the same as self-leveling compound?
Floor leveler is the common name for self-leveling compound: a pourable cement-based mix that flows flat and cures into a smooth base for tile, vinyl or wood. Other levelling products, such as patch compounds, cover differently, which is why the charts use the same divide-and-round-up arithmetic but different coverage figures — always enter the coverage for the product you will actually use.
Why add 10% waste?
Because material is lost to spillage, over-pour and feathering at edges and drains: the 10% allowance covers the compound that never ends up as a finished level surface. Without it, a job that computes to exactly 17.60 bags would run dry on the last stretch of floor, and the waste percentage is what keeps the order honest for real pouring.
Why round up instead of to the nearest bag?
Because a partial bag cannot be bought in the quantity needed, and rounding down leaves floor unlevelled: 17.60 bags rounded to the nearest is 18 here, but a 17.40-bag job rounded to the nearest is 17, and 17 bags cover only 425 of the 440.00 square feet needed. Rounding up guarantees the whole area is covered; the extra fraction is the price of buying whole bags.
What if the exact figure is already a whole number?
Then you order exactly that many: a job of 25 square feet at 0% waste needs exactly 1.00 bag and orders 1, not 2, and the epsilon in the rounding protects exact fits, so a job that lands on a whole number is not charged an extra bag for nothing.
Does the waste allowance cover a second pour?
No: waste and pours are different things. Waste is the extra 10% for spillage, over-pour and feathering on one pour; a second pour doubles the area first, so 400 square feet twice-levelled is 800 square feet before waste, which is 880.00 square feet with waste and 35.20 bags, order 36. Decide the pours first, then let waste stay at waste.