Get bags and volume from floor area and fill depth. Compare three brands, model a low spot, and check your units.
Estimated whole bags
6 bags
CUSTOM LevelQuik RS · 50 lb each
Net fill volume
2.500 ft³
70.79 L · before allowance
With 10% allowance
2.750 ft³
Lower coverage used for ordering
Example estimate: 120 ft² × 1/4 in, with 10% extra. Change the measurements below.
Same floor, three product yields
Official coverage → bags at your depth
Each row recalculates from your current area, average depth and allowance. The open functions use A in ft², d in inches and w as a percent. A range reflects the manufacturer's coverage range, not a confidence interval.
Product / official basis
Open bag function
Your order
CUSTOM LevelQuik RS · 50 lb23–24 ft² at 1/4 in [1]Derived capacity: 5.75–6 ft²·in/bag Equivalent yield: 0.479167–0.500000 ft³/bag
low = ceil(A × d × (1+w/100) / 6)order = ceil(A × d × (1+w/100) / 5.75)Order uses the lower coverage endpoint.
6whole bags23–24 ft²/bag at your depth
ARDEX V 1200 · 50 lb25 ft² at 1/4 in [2]Derived capacity: 6.25 ft²·in/bag Equivalent yield: 0.520833 ft³/bag
order = ceil(A × d × (1+w/100) / 6.25)Check primer-dependent depth limits.
6whole bags25 ft²/bag at your depth
SikaLevel (US) · 50 lb21 ft² at 1/4 in [3]Derived capacity: 5.25 ft²·in/bag Equivalent yield: 0.437500 ft³/bag
order = ceil(A × d × (1+w/100) / 5.25)Uses the inch-based 1/4-in reference.
7whole bags21 ft²/bag at your depth
Coverage is approximate. Functions scale the stated 1/4-in reference by volume; other depths are calculated estimates, not additional manufacturer test points. Printed metric equivalents in product sheets are rounded. We keep one inch-based reference per product and use exact unit conversions instead of blending incompatible rounded figures. No aggregate extension is modeled.
Choose the depth that describes your floor
Known average
For a uniform layer, or an average you have already measured. Do not substitute the deepest spot across the whole floor.
d̄ = entered average depth
Local wedge
For a rectangular low strip that slopes steadily downward. Base depth applies everywhere; only the chosen footprint gets the additional wedge fill. A bowl is a different shape.
d̄ = base + (footprint% / 100) × extra gap / 2
Four-corner taper
For a rectangular patch with smooth, bilinear depth variation. Measure A–D relative to one target plane. Irregular floors need a denser survey; corner readings can miss the middle.
d̄ = (A + B + C + D) / 4
These are fill-volume models, not instructions to make a sloping finished surface. Minimum local depth, maximum local depth and average thickness are different checks. A low average cannot make an excessively deep pocket acceptable.
Before ordering
Catch the unit mix traps
Your measurements, in both systems
Area: 120 ft² = 11.1484 m² Average: 0.25 in = 6.35 mm
Changing an area or depth unit converts the existing measurements. It does not reinterpret the same number in a different unit.
A quarter inch is 0.25 in. 0.4 in is 60% deeper. A quarter foot is 3 in—12 times the intended depth. 1/8 in is exactly 3.175 mm, not exactly 3 mm.
0 of 5 checked · personal reminders, not product approval.
Worked example: a 120 ft² floor
Use a 1/4-in average depth, CUSTOM LevelQuik RS and an illustrative 10% allowance.
These synthetic examples illustrate the geometry; they are not measurements of a real floor.
Uniform: 0.25 in Local wedge: 0.125 + 0.50 × 0.5 / 2 = 0.25 in Four corners: (0.125 + 0.375 + 0.375 + 0.125) / 4 = 0.25 in
In the wedge example, applying its 0.625-in deepest fill everywhere would give 6.25 ft³ net and 15 bags with 10% extra. The modeled wedge gives 2.5 ft³ and 6 bags. That difference depends on the stated shape and footprint.
Official sources & calculation notes
US product references checked 24 October 2026. Use the current sheet for the exact package sold in your market. These figures estimate material quantity; they do not approve a substrate or installation system.
Published 18 January 2024; coverage table on page 5: 23–24 ft² per 50 lb bag at 1/4 in. Describes featheredge to 1.5 in in one pour; substrate-specific requirements still apply. All surfaces require the specified primer.
Updated 2 April 2026; page 7: 25 ft² at 1/4 in per 50 lb bag. Page 5 gives 1/4-in average minimum, with taper exceptions, and primer-dependent maxima: 1/4 in over VB 100, 1/2 in over P 82 or P 4, and 2 in in other stated cases. The calculator does not select a primer or determine exceptions.
May 2026, version 01.06; pages 1–2: 50 lb bag, 21 ft² at 1/4 in, 1/8–2 in layer range with the deeper application described as localized. The calculator derives 0.4375 ft³ from this one reference; it does not combine other rounded coverage rows. See all limitations and Sika Level Primer requirements.
Net ft³ = area in ft² × average depth in inches ÷ 12. One foot is 0.3048 m; one inch is 25.4 mm; one ft³ is 28.316846592 L. Bag calculations use exact rational arithmetic for accepted decimal/fraction inputs, with rounding only for display and the final whole-bag ceiling. Actual coverage varies with substrate profile, losses and placement. Extra material is user-selected, not a guaranteed manufacturer waste rate. Mixing water, primer, aggregate, labor and costs are separate quantities.
Common questions
How many bags cover 120 ft² at 1/4 inch?
Before extra material, this example needs 6 whole bags of each listed product. With 10% extra, the result is 6 LevelQuik RS, 6 ARDEX V 1200, or 7 SikaLevel bags. Choose one product; these are alternatives.
Can I use four corners for an uneven floor?
Only when the rectangle is reasonably represented by smooth bilinear depth variation. A center depression can be invisible at the corners. Survey more points and estimate separate patches when that assumption fails.
Does “self-leveling concrete” mean structural concrete?
This calculator estimates cementitious self-leveling underlayment for floor preparation using the listed products. It does not design structural slabs, determine load capacity or replace the manufacturer's installation instructions.
Why can a tiny depth change add a whole bag?
Bags are whole purchases. Once the unrounded requirement passes an integer, the next whole bag is needed. The display may round two nearby volumes to the same number; the bag calculation still uses their unrounded values.