Select the exact product
Check the current technical data sheet for the manufacturer, bag weight, reference coverage, allowable depth and primer requirements.
Measure it this way Not to scale · Measure the actual space to be filled, not a guessed outside dimension.
Self-leveling underlayment estimator
Select a verified ARDEX K 15 reference, or switch to Custom to enter your own unverified coverage and depth limits.
The calculation method
How to estimate self-leveling compound bags
For these products, the manufacturer often states floor area covered per bag at a reference thickness—not simply a concrete cubic-yard yield.
Measure areas and average pour thickness
Compute a weighted quantity from zones of distinct depth, such as kitchen low spots versus the rest of a room.
Scale coverage before rounding
Theoretical bags = (area ÷ stated coverage per bag) × (actual depth ÷ reference depth). Sum compatible same-product zones, then apply allowance and round up.
Worked example
Worked example: ARDEX K 15 at half an inch
ARDEX K 15 55 lb is listed at approximately 30 ft² per bag at 1/4-inch thickness. A 100 ft² floor poured at an average 1/2 inch needs approximately 6.6667 theoretical bags, so 7 whole bags before loss allowance.
Check the arithmetic
- Reference: ~30 ft²/bag at 0.25 in
- Depth adjustment: 100 ÷ 30 × (0.5 ÷ 0.25) ≈ 6.6667
- Purchase rounding: ceil(6.6667) = 7 bags without allowance
Review the assumptions. These are mathematical examples, not live material orders, current supplier quotes or structural design recommendations.
Buying and measurement guidance
What can make a flooring coverage estimate inaccurate?
Self-leveling compound does not behave like regular concrete mix, and a general estimator cannot replace a product installation system.
Different floor elevations
A single average thickness can be too optimistic if extensive floor areas have deep low spots. Split the room into realistically measured depth zones.
Minimum and maximum permitted layers
The default K 15 range is based on product information and must be checked against the latest data sheet, chosen application and any aggregate extension.
Surface preparation and primer
Substrate, moisture, waterproofing, primer system and water mix ratio are product-specific. The calculator estimates bags, not an approved installation method.
Next project decision
Self-leveling coverage depends on the exact product
Floor-leveling compounds are not interchangeable with standard concrete mix: check the specific coverage and allowable layer thickness first.
- Measure the true average depth over each area instead of relying only on the largest dip in the floor.
- Verify the exact brand, product data sheet, substrate preparation and minimum/maximum lift restrictions.
- Apply the product-specific coverage rate, then round up to sealed whole bags using your chosen material allowance.
Frequently asked questions
Self-Leveling Concrete Calculator FAQs
Answers to real measurement and purchase questions. Product data and field conditions can change actual requirements.
Can I use regular 80 lb concrete bags for self-leveling?
No. Self-leveling underlayment is a specialized formulation with distinct manufacturer coverage and installation requirements.
How do I calculate several rooms?
Add one zone for each area with a reasonably consistent mean depth, using the same chosen product for all zones in that calculation.
Can I manually change the product coverage?
For the built-in ARDEX K 15 preset, coverage and permitted thickness limits are locked to its published reference assumptions. Choose Custom coverage to enter values from the current technical data sheet for your exact product. Custom values are not manufacturer-approved by this website.
Does the calculator include primer and water?
No. Primer compatibility, water dosage and drying time must be taken directly from the product-specific current technical data sheet.
Accuracy checklist
Before you order materials
These checks apply to the calculator above and help prevent expensive mistakes.
Units are labeled
ft / in / ft³ / yd³ and product bag coverage all mean different things. Change a value only when you know the unit.
Net, waste and purchase are separate
The geometric amount, adjusted quantity and supplier purchase increments should not be mistaken for one another.
Sources must fit the chosen material
Official product data is a starting point for planning. Check installation specifications and local requirements before use.
Continue your project
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Choose the next task rather than making one calculator answer every question.
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Methods and references
Source material and limitations
See the sources behind named product assumptions. These are not endorsements or live quotes.
Transparency: Calculators provide mathematical planning estimates. Product availability, real mixed yield, structural design, code requirements, and on-site conditions need independent verification. Always confirm current product specifications, installation instructions and local supplier requirements before purchasing.