Compare the boxes you need to buy
A price per square foot describes a product, but your room determines how many complete boxes you purchase. If your target area is slightly larger than the coverage of five boxes, this calculator uses six boxes. It rounds the required quantity up separately for A and B, then multiplies by each box price. A smaller box can therefore cost less for your project even when its price per square foot is higher.
Use square feet for every area and US dollars for both prices. Enter the coverage printed on one package, not the length and width of a plank or the coverage of a pallet. If a seller uses packs instead of boxes, a pack can be your purchase unit as long as the coverage and price both refer to that same complete pack. This model assumes you can buy any whole number of those units. It does not model minimum pallet orders, split packs or volume discounts.
Measure once and add an allowance only once
For a rectangular room, multiply length by width after converting both measurements to feet. Ten feet six inches is 10 + 6 ÷ 12 = 10.5 feet, so a room that is 10 ft 6 in by 8 ft has an area of 84 ft². For an L-shaped floor, divide the floor into rectangles and add their areas without counting overlapping sections twice. The calculator accepts the final area you enter; it does not draw the room or infer dimensions.
The optional percentage increases the measured area before the box count is rounded up. The target is room area × (1 + allowance ÷ 100). An entered allowance of 10% changes 100 ft² into a target of 110 ft². That percentage is an arithmetic example, not a fixed recommendation. The input starts blank, meaning 0%. Choose a value for your material, cutting pattern and installer guidance. If the area already includes your desired reserve, leave the allowance blank or use 0 to avoid adding it twice.
Worked example: lower unit price, higher purchase cost
For a 100 ft² room with an entered 10% allowance, Product A covers 20 ft² per box and costs $30. The 110 ft² target needs 110 ÷ 20 = 5.5 boxes, rounded up to 6 boxes. They cover 120 ft² and cost $180.00. Purchased coverage is 20 ft² above the room and 10 ft² above the allowance target.
Product B covers 80 ft² per box and costs $116. Its unit price is $1.45 per ft², compared with A's $1.50. However, B needs 2 boxes, covering 160 ft² for $232.00. A's whole-box material cost is $52.00 lower. Those are illustrative inputs, not current product prices. The result does not include shipping, sales tax or installation; these extra costs could change which quote is lower overall.
Two different measures of extra coverage
Coverage above the room equals purchased coverage minus the measured room area. It includes the allowance you chose plus any additional coverage caused by buying whole boxes. Coverage above the allowance target subtracts that larger target instead. It shows only the extra coverage caused by whole-box rounding. Both measures are useful when checking your order, but neither tells you how much usable material will remain after cuts.
The model assumes each box supplies its stated coverage. It does not arrange boards, estimate which offcuts can be reused, assess installation suitability or determine a safe cutting allowance. Damaged pieces, pattern matching, transitions and installation methods can change actual requirements. Keep any reserve you want in the target and confirm your measurements and packaging before ordering. Unopened-box returns and refunds are not included.
Precision and incomplete inputs
Room area and box coverage accept up to four decimal places and a maximum of 1,000,000 ft². Coverage must be greater than zero. The allowance accepts 0%–100% with up to two decimal places; blank means 0%. Box prices accept $0–$1,000,000 with up to two decimal places. Properly grouped thousands separators are allowed. A blank required value removes the previous result instead of treating it as zero. With an explicit zero room area, both products need zero boxes and have zero material cost.
Decimal inputs are converted to whole-number units before division. For example, a 0.07 ft² target divided by 0.01 ft² coverage requires exactly seven boxes, rather than an extra box caused by a floating-point rounding error. The allowance target can have up to eight decimal places because area and percentage are multiplied. Money is calculated in whole cents. Combinations that exceed the supported exact-integer range are rejected instead of displaying unreliable totals.
Frequently asked questions
Why can a lower price per square foot cost more?
You buy whole boxes. In the worked example, A needs six $30 boxes for $180, while B needs two $116 boxes for $232 even though B has a lower unit price. The result compares the material purchase for the same room and allowance.
How much extra flooring should I enter?
Choose an allowance for your material and layout using your product or installer guidance. Blank means 0%; no recommended rate is built in. If your area already includes an allowance, leave the extra percentage blank or enter 0 to avoid counting it twice.
Does this include installation, shipping or sales tax?
No. The comparison includes only whole boxes at the USD prices you enter. Installation, shipping, sales tax, underlayment, tools and removal are separate costs. Check them in your actual quotes.
Does extra coverage mean usable spare boards?
No. Coverage above the room includes your allowance and whole-box excess. Coverage above the target shows only whole-box excess. Cuts and layout determine whether any remaining boards can be used.