20 m² with a 10% allowance
20 × 1.10 = 22 m²
At 2.2 m² per box, the estimate is exactly 10 boxes. At a price of 30 per box, material cost is 300.00 in the same currency. These are illustrative product inputs.
Home projects
Flooring Calculator
Turn floor area into whole boxes of flooring. Set your extra allowance, use the coverage printed on your product, and optionally estimate material cost.
Estimate flooring boxes
Whole boxes needed
Area estimateEnter a floor area and coverage per box to estimate your purchase.
- Floor area before allowance
- Extra allowance area
- Required coverage including allowance
- Coverage from purchased boxes
- Surplus above allowance-inclusive estimate
- Estimated material cost (your currency)
≈ marks display rounding. Calculations run in your browser. Press Enter to calculate. Successful results appear in this tab's Recent calculations.
Flooring purchase examples
12 ft × 10 ft
120 × 1.10 ÷ 23 = 5.739…
The floor area is 120 ft² and the chosen 10% allowance increases required coverage to 132 ft². With 23 ft² per box, buy 6 boxes in this model: 138 ft² of coverage, with 6 ft² above the allowance-inclusive estimate.
20.01 m² at 2 m² per box
20.01 ÷ 2 = 10.005 → 11 boxes
With zero allowance, ten boxes cover only 20 m². Even a small amount beyond that requires an 11th box. The calculation uses the full input precision before rounding the displayed area.
Formulas, conversions, and estimate limits
For a rectangular room, floor area = length × width after converting both measurements to meters. For a known area, convert directly to square meters. Extra allowance area = floor area × allowance ÷ 100. Required coverage = floor area + extra allowance area.
Whole boxes needed = required coverage ÷ coverage per box, rounded upward to the next integer when there is a remainder. Purchased coverage = whole boxes × coverage per box. Surplus = purchased coverage − required coverage. This surplus is additional to the chosen allowance; it is not a prediction of usable leftover planks.
Material cost = whole boxes × price per box. A blank price omits cost; a price of zero gives 0.00. Use one currency throughout. There is no currency conversion, and the estimate excludes taxes, shipping, labor, underlayment, trim, and other accessories. Cost is always rounded to two decimal places for display, which may differ from the minor-unit convention used by your currency or seller.
Conversions use exact international definitions: 1 ft = 0.3048 m and 1 in = 0.0254 m. Therefore 1 ft² = 0.09290304 m². Each dimension and the coverage per box can use different units. An input-unit change reinterprets the typed number; an area-result-unit change converts the existing answer.
Area, active room dimensions, and box coverage must be positive. Allowance is from 0 to 100%, with blank treated as zero. Price must be zero or greater if supplied. Inputs accept up to 64 characters, 15 integer digits, and 10 decimal places. Expressions, scientific notation, fractions, and unit symbols are not accepted. Hidden inputs for the other area mode are ignored.
Calculations retain exact fractions, and whole boxes use the unrounded requirement. Displayed areas use the selected maximum decimal places, with trailing zeros removed. Halfway values round away from zero; ≈ identifies display rounding. Increasing area precision does not change the box count or the fixed two-decimal cost display.
This is an area-based estimate for one selected flooring product. It does not optimize cuts, plank direction, patterned layouts, tile grout spacing, or reuse of offcuts. It does not verify subfloor condition, product suitability, installation clearances, or manufacturer requirements. An allowance is your input, not a guarantee that the resulting boxes will be sufficient for every layout. Follow the product instructions and installation plan before purchasing.
References: Pergo — measuring floor area and product installation instructions, Pergo — an example product specification with coverage per carton, and NIST — exact international length definitions. Enter the current coverage for the product you intend to buy; no product coverage or price is fetched automatically.
Common questions
Does box coverage mean the area of one plank?
No. Enter the total area covered by all flooring pieces in one complete box or carton. Check the label or product specification; box contents and coverage differ by product.
Is 10% extra always enough?
No. It is an editable example. The amount depends on the product, room shape, installation pattern, cuts, and whether you want spare pieces. Follow the manufacturer's instructions and your installer's plan.
Can I combine several rooms?
Yes, if you have already added their non-overlapping floor areas and intend to use the same product and allowance. Enter the combined value in known-area mode. Different products or installation assumptions need separate estimates.
Why is there surplus when I already included an allowance?
Flooring is usually sold in whole boxes. Rounding up to the next box can add more coverage than the floor area plus your allowance. Surplus here is only that extra amount above the allowance-inclusive requirement.
Does the result tell me how to cut or arrange planks?
No. It compares total area with box coverage. A layout can need more material even when total area appears sufficient, so check plank sizes, pattern, direction, and usable offcuts separately.