On this page
AnswerCoverage the sheets printArea times depth, divided by the bag yieldBags for 50 to 500 square feetTen percent is the calculator default, not the sheetSquare metres, millimetres and a 25 kg bagWhat the calculator opens onWorked example — 100 sq ft at 1/8 in, LevelQuik RS, waste 0
100 × (1/8) ÷ 12 = 100/96 = 1.041666… ft³. At 46 sq ft per bag, 100 ÷ 46 = 2.173…, so the order rounds up to 3 bags. At 48 sq ft per bag, 100 ÷ 48 = 2.083…, which also rounds up to 3 bags. The yields are 46/96 ft³ and 0.5 ft³. HENRY 555 at the same floor is a 40 lb bag: 100 ÷ 43 = 2.325…, which rounds up to 3 bags. ARDEX K 15 is a different depth on its sheet. At 6 mm, 9.290304 m² ÷ 2.8 m² = 3.317…, which rounds up to 4 of the 25 kg bags.
Flooring calculator
Self-leveling calculator
Self-leveling bags from floor area, pour depth and the bag yield printed on the sack.
By Feroz Sheikh · Formula FLOOR-SLU-001 v1.0.0 · Tested formula
FLOOR-SLU-001v1.0.0Project inputs
Enter your measurements. Switching units converts the same project, including coverage and unit rates. Package yields keep the unit printed beside each field.
Calculated result
Bags to mix
FLOOR-SLU-001bags = ceil(L × W × depth × (1 + waste) ÷ bag yield)
Pour volume
Volume including waste
Floor area
Planning estimate, not engineering advice. Confirm site measurements and product specifications. Calculation limits.
Floor area times pour depth, divided by the bag yield printed on the sack, after waste, rounded up to whole bags.
- Measure the floor that will receive the pour, not the room including cabinets you will float around.
- Depth is the average. Low spots eat extra — that is the waste field.
- Thinset and grout stay tile companions.
Add your project costs
Enter supplier prices and any labour, equipment or delivery costs. Pick a currency — badges, inputs, and totals follow.
Costs use the carton or square-foot rate you type. Construclytic does not fetch store prices. Underlayment, grout, thinset and labour stay companion lines.
Coverage the sheets print
These are premixed self-leveling underlayments. Each row is one sheet, opened 1 November 2026. None of the sheets is averaged into the others. A 50 lb bag and a 40 lb bag do not share a coverage line.
Custom Building Products LevelQuik RS, TDS-108, published 18 January 2024, is a 50 lb (22.68 kg) bag. The coverage chart prints 46–48 ft² (4.2–4.4 m²) at 1/8 in (3.18 mm), 23–24 ft² (2.1–2.2 m²) at 1/4 in (6.35 mm), 11.5–12 ft² (1.05–1.1 m²) at 1/2 in (12.7 mm), 5.75–6 ft² (0.52–0.55 m²) at 1 in (25.4 mm), and 3.8–4 ft² (0.35–0.37 m²) at 1.5 in (38.1 mm). The sheet says the chart is for estimating and that coverage may vary with installation and jobsite conditions. It does not print a 3/8 in row. The 1/4 in, 1/2 in and 1 in rows are exactly 46–48 divided by 2, 4 and 8. The 1.5 in low end prints 3.8, while 46 ÷ 12 = 3.833…, so that cell is rounded. The area table stops at 1 in, where the printed numbers and the division agree.
HENRY 555 LevelPro, technical data dated 15 May 2025, mixes one 40 lb bag with 5 quarts of water. The coverage line is 43 square feet at 1/8 in thickness. That is the only coverage figure on the sheet. A 100 sq ft floor at 1/8 in is 100 ÷ 43 = 2.325…, which rounds up to 3 of those 40 lb bags, before waste. The sheet prints a 1/8 in minimum over the highest points for maximum smoothing, and it also says mixed material may be featheredged to match an existing elevation. Pours thicker than 1 1/2 in on that sheet take aggregate, which the sheet says diminishes workability. This page does not turn the single 43 sq ft line into a 1/4 in or 1/2 in Henry coverage.
Sakrete Self-Leveling Underlayment is a 50 lb (22.7 kg) bag. The data sheet prints 50–60 ft² (4.5–5.8 m²) at 1/8 in (3 mm), 25–30 ft² (2.3–2.8 m²) at 1/4 in (6 mm), and 12–15 ft² (1.1–1.4 m²) at 1/2 in (12 mm). The sheet does not print a revision date; the footer includes ©2006. The product page opened the same day repeats 25–30 ft² at 1/4 in deep, and it says the pour is 1/8 in to 1 in in a single lift. Half of the 1/4 in low end would be 12.5 sq ft at 1/2 in. The sheet prints 12. This page does not extend Sakrete to 3/8 in or 1 in. At 100 sq ft and 1/2 in, 100 ÷ 12 = 8.333… rounds up to 9 bags and 100 ÷ 15 = 6.666… rounds up to 7 bags.
ARDEX K 15, content updated 2 April 2026, is a 55 lb (25 kg) bag. Coverage is 30 sq ft (2.8 m²) per bag at 1/4 in (6 mm), and the sheet says that figure depends on surface profile, density and porosity. It also says a 1/8 in minimum over the highest point will typically result in an average thickness of at least 1/4 in. The 1/8 in column below is LevelQuik’s printed coverage. It is a LevelQuik quantity, and it is a separate question from an ARDEX average thickness. 30 × 0.09290304 = 2.7870912 m², so the printed 2.8 m² is rounded. A 241 sq ft floor at 1/4 in is 241 ÷ 30 = 8.033…, which rounds up to 9 bags, and 241 × 0.09290304 = 22.38963264 m², which is 22.38963264 ÷ 2.8 = 7.996… and rounds up to 8 bags.
| Product | Bag | What the sheet prints |
|---|---|---|
| LevelQuik RS, TDS-108, 18 January 2024 | 50 lb (22.68 kg) | 46–48 ft² at 1/8 in; 23–24 at 1/4 in; 11.5–12 at 1/2 in; 5.75–6 at 1 in |
| HENRY 555 LevelPro, 15 May 2025 | 40 lb | 43 ft² at 1/8 in |
| Sakrete Self-Leveling Underlayment | 50 lb (22.7 kg) | 50–60 ft² at 1/8 in; 25–30 at 1/4 in; 12–15 at 1/2 in |
| ARDEX K 15, updated 2 April 2026 | 55 lb (25 kg) | 30 ft² (2.8 m²) at 1/4 in (6 mm) |
Area times depth, divided by the bag yield
Sq ft of coverage and cubic feet of yield describe the same bag when the depth is the depth on the chart. Cubic feet = sq ft × depth in inches ÷ 12. Bags = ceil(cubic feet × (1 + waste) ÷ yield in ft³). Waste in that line is a decimal, so 10% is 0.10. The calculator’s waste field is the percent: type 10 and the tool divides by 100 before it multiplies. Depth in the imperial calculator is inches. Bag yield stays cubic feet in both unit systems.
LevelQuik’s low end at 1/8 in is 46 sq ft, so the yield is 46 × (1/8) ÷ 12 = 46/96 ft³. Rounded half up to 8 decimal places, 46/96 = 0.47916667 ft³. The high end is 48/96 = 0.5 ft³ exactly. A 100 sq ft floor at 1/8 in is 100 ÷ 96 = 1.041666… ft³. Dividing by 46/96 returns 100 ÷ 46 = 2.173…, which rounds up to 3 bags. Dividing by 0.5 returns 2.083…, which also rounds up to 3 bags. The linked calculator enters 10 ft × 10 ft, depth 0.125 in, yield 0.5 ft³ and waste 0, and it reports 3 bags.
The 3/8 in column uses the same yields. Coverage at the low end is 46 ÷ 3 = 15.333… sq ft. At the high end it is 48 ÷ 3 = 16 sq ft. Those two numbers are calculated. They are not a printed LevelQuik row. A 200 sq ft floor at 3/8 in is 200 × 3 ÷ 46 = 13.043…, which rounds up to 14 bags, and 200 × 3 ÷ 48 = 12.5, which rounds up to 13 bags.
Bags for 50 to 500 square feet
Every cell is waste 0. The low-coverage end is 46 sq ft at 1/8 in, then that coverage divided by 2, 3, 4 or 8. The high-coverage end is 48 sq ft at 1/8 in, divided the same way. One number means both ends round up to the same bag count. Two numbers are the low-coverage end, then the high-coverage end. A 500 sq ft floor at 1/8 in is 500 ÷ 46 = 10.869…, which rounds up to 11, and 500 ÷ 48 = 10.416…, which also rounds up to 11.
Primer, lath, aggregate above the neat thickness, and a second lift are separate products or extra volume. The LevelQuik sheet says a second layer, when required, is installed immediately after the first. This table is one depth over the measured floor. Cabinets you will not pour stay out of the area. Low spots belong in the waste field, once.
| Floor | 1/8 in | 1/4 in | 3/8 in | 1/2 in | 1 in |
|---|---|---|---|---|---|
| 50 sq ft | 2 | 3 | 4 | 5 | 9 |
| 100 sq ft | 3 | 5 | 7 | 9 | 18 / 17 |
| 150 sq ft | 4 | 7 | 10 | 14 / 13 | 27 / 25 |
| 200 sq ft | 5 | 9 | 14 / 13 | 18 / 17 | 35 / 34 |
| 300 sq ft | 7 | 14 / 13 | 20 / 19 | 27 / 25 | 53 / 50 |
| 500 sq ft | 11 | 22 / 21 | 33 / 32 | 44 / 42 | 87 / 84 |
Ten percent is the calculator default, not the sheet
The four sheets opened for this page describe coverage as approximate or dependent on the surface. None of them prints a waste percentage. The self-level calculator’s waste field defaults to 10% and its hint calls that an allowance for low spots, mixing loss and a spare bag. The table below applies that 10% once, on the LevelQuik low-coverage end only: bags = ceil(sq ft × 1.10 ÷ coverage). A second 10% after the bags are already whole counts the same allowance twice.
A 200 sq ft floor at 1/4 in is 9 bags at 23 sq ft per bag with waste 0. With 10%, the area is 220 sq ft, and 220 ÷ 23 = 9.565…, which rounds up to 10 bags. A 500 sq ft floor at 1/8 in moves from 11 bags to 12: 550 ÷ 46 = 11.956…. The high-coverage end is left out of this table so the 10% is not stacked on top of the gap between 46 and 48.
| Floor | 1/8 in | 1/4 in | 3/8 in | 1/2 in | 1 in |
|---|---|---|---|---|---|
| 50 sq ft | 2 | 3 | 4 | 5 | 10 |
| 100 sq ft | 3 | 5 | 8 | 10 | 20 |
| 150 sq ft | 4 | 8 | 11 | 15 | 29 |
| 200 sq ft | 5 | 10 | 15 | 20 | 39 |
| 300 sq ft | 8 | 15 | 22 | 29 | 58 |
| 500 sq ft | 12 | 24 | 36 | 48 | 96 |
Square metres, millimetres and a 25 kg bag
The same six floors, converted with 1 ft² = 0.09290304 m², are 4.645152, 9.290304, 13.935456, 18.580608, 27.870912 and 46.45152 m². ARDEX K 15 is the 25 kg bag in this table. The only printed coverage is 2.8 m² at 6 mm. The other thicknesses use 2.8 × 6 ÷ millimetres: 5.6 m² at 3 mm, 16.8 ÷ 9 = 1.8666… m² at 9 mm, 1.4 m² at 12 mm, and 16.8 ÷ 25 = 0.672 m² at 25 mm. Bags = ceil(m² × mm ÷ 16.8), with waste 0. ARDEX prints 1/4 in as 6 mm, so this table uses 3, 6, 9, 12 and 25 mm rather than 3.175, 6.35, 9.525, 12.7 and 25.4.
On these six floors at 6 mm, ceil(m² ÷ 2.8) matches ceil(sq ft ÷ 30). A 100 sq ft floor is 9.290304 m², and 9.290304 ÷ 2.8 = 3.317…, which rounds up to 4 bags of the 25 kg sack. The 241 sq ft case above shows the rounded 2.8 m² and the printed 30 sq ft can still land on different whole bags. This table uses 2.8. The yield behind that printed point is 2.8 × 0.006 = 0.0168 m³. The calculator stores bag yield in cubic feet. The printed 30 sq ft at 1/4 in is 30 × (1/4) ÷ 12 = 0.625 ft³. Enter 0.625 when you are following the 30 sq ft line.
LevelQuik’s printed m², 4.2–4.4 at 1/8 in and the matching rows, are rounded. 46 × 0.09290304 = 4.27353984 m², which the sheet prints as 4.2. The imperial bag table uses 46 and 48. Dividing the converted square metres by 4.2 would be a different order.
| Floor | m² | 3 mm | 6 mm | 9 mm | 12 mm | 25 mm |
|---|---|---|---|---|---|---|
| 50 sq ft | 4.645152 | 1 | 2 | 3 | 4 | 7 |
| 100 sq ft | 9.290304 | 2 | 4 | 5 | 7 | 14 |
| 150 sq ft | 13.935456 | 3 | 5 | 8 | 10 | 21 |
| 200 sq ft | 18.580608 | 4 | 7 | 10 | 14 | 28 |
| 300 sq ft | 27.870912 | 5 | 10 | 15 | 20 | 42 |
| 500 sq ft | 46.45152 | 9 | 17 | 25 | 34 | 70 |
What the calculator opens on
The calculator on this page opens at 12 × 10 ft, 1/8 in, 0.40 ft³ per bag and 10% waste, which is 4 bags. That 0.40 ft³ is the planning default in the tool. It is not the LevelQuik yield, not the Henry 43 sq ft line, and not the ARDEX 0.625 ft³ line. Replace it with the yield from the sack in your hand. The 100 sq ft link in the first paragraph sets 0.5 ft³ and waste 0.
Formula FLOOR-SLU-001 is area × depth, then waste, then one round-up. Thinset and mortar are other sacks. Measuring the laminate or the carpet does not set the pour depth. How to estimate laminate flooring cartons keeps the carton count on its own line, and the flooring planning guide is the hub for the other flooring counts.
Do it in order
- Read the coverage at your depth on the data sheet for the bag you will buy, and note the bag weight next to it.
- Divide the floor area by that coverage, or multiply area by depth and divide by the bag yield in the same units.
- Apply one waste allowance, if you use one. These sheets do not print a percentage. The calculator default of 10% is an example.
- Round up to a whole bag. Keep primer, lath and any aggregate extension on their own lines.
Planning boundary
This is a bag count from published coverage and from stated conversions. It does not choose a pour thickness, a primer, a flatness tolerance or an installation warranty. Confirm the sack in your hand, including its minimum and maximum thickness.
Sources checked
Each link supports the point named in the text. A citation is not a product endorsement or a price for your site.
- Custom Building Products — LevelQuik RS, TDS-108, published 18 January 2024 (opened 1 November 2026)
- The W.W. Henry Company — 555 LevelPro technical data, 15 May 2025 (opened 1 November 2026)
- ARDEX — K 15 technical data, content updated 2 April 2026 (opened 1 November 2026)
- Sakrete — Self-Leveling Underlayment data sheet; no revision date printed, footer ©2006 (opened 1 November 2026)
- Sakrete — Self-Leveling Underlayment product page, 25–30 ft² at 1/4 in (opened 1 November 2026)
How many bags of self-leveling compound per square foot?
LevelQuik RS, TDS-108 published 18 January 2024, covers 46–48 sq ft per 50 lb bag at 1/8 in and 23–24 sq ft at 1/4 in, before waste. Bags = ceil(sq ft ÷ that coverage). Henry 555, a 40 lb bag, prints 43 sq ft at 1/8 in. Sakrete’s 50 lb bag prints 50–60 sq ft at 1/8 in and 25–30 sq ft at 1/4 in. Use the line on your bag.
How many bags of self-leveler for 100 square feet at 1/8 inch?
3 bags of LevelQuik RS at either 46 or 48 sq ft per bag, before waste. 100 ÷ 46 = 2.173… and 100 ÷ 48 = 2.083…. Henry 555 at 43 sq ft is also 3 bags. Sakrete at 50–60 sq ft is 2 bags, because 100 ÷ 50 = 2 and 100 ÷ 60 rounds up to 2.
How many bags of self-leveler at 1/4 inch for 100 square feet?
5 bags of LevelQuik RS at either 23 or 24 sq ft per bag, before waste. 100 ÷ 23 = 4.347… and 100 ÷ 24 = 4.166…. Sakrete at 25–30 sq ft is 4 bags. ARDEX K 15 at its printed 6 mm covers 2.8 m² per 25 kg bag, and the same 100 sq ft is 9.290304 m², which rounds up to 4 bags.
How many 25 kg bags of self-levelling compound per square metre?
ARDEX K 15, updated 2 April 2026, prints 2.8 m² per 25 kg bag at 6 mm. Bags = ceil(m² ÷ 2.8) before waste. A 10 m² floor at 6 mm is 10 ÷ 2.8 = 3.571…, which rounds up to 4 bags. Thicknesses other than 6 mm on this page are 2.8 × 6 ÷ mm, calculated from that one printed point.
Should I add waste on top of the coverage chart?
The charts are estimating coverage. The main table leaves waste at 0 so that coverage stays visible. An illustrative 10%, which is the calculator’s default, is applied once to the area. A 200 sq ft floor at 1/4 in moves from 9 bags to 10 bags at 23 sq ft per bag. The sheets checked on 1 November 2026 do not print that 10%.