Flooring Calculator
Enter the size of your room, how much waste to allow and how many square feet are in a box to see how much flooring to buy. Add a price per square foot to estimate the cost.
How to use this flooring calculator
- Measure the length and width of the room. For an L-shape or several rooms, calculate each section and add the results, or use the Square Footage Calculator.
- Subtract any area that will not be covered, such as a built-in cabinet.
- Keep the 10 percent waste or adjust it for your layout. Planks laid on an angle, short rooms and many doorways all use more material.
- Enter the coverage per box from the product label and, if you like, a price per square foot.
- Press Calculate. Use Copy result or Export CSV to compare products or send the numbers to a supplier.
How to calculate how much flooring you need
The calculator finds the floor area, adds waste, and rounds up to whole boxes.
- Room area = length (ft) x width (ft) minus any area you leave out
- Flooring to buy = room area x (1 + waste % / 100)
- Boxes = flooring to buy / coverage per box, rounded up
- Cost = boxes x coverage per box x price per square foot
The cost uses whole boxes because that is how most flooring is sold.
Worked example
A room is 15 ft by 12 ft, so the area is 180 sq ft. With 10% waste you need 180 x 1.10 = 198 sq ft. A box covers 20 sq ft, so 198 / 20 = 9.9, which rounds up to 10 boxes. That is 200 sq ft of flooring. At $3.50 per square foot the cost is 10 x 20 x 3.50 = $700.00.
The 2 sq ft left over after the job is useful for repairs later, so keep it with the leftover boxes.
Assumptions & limits
- The room is a rectangle. Odd shapes need to be split into sections.
- The default coverage of 20 sq ft per box is an editable placeholder. Boxes of laminate, vinyl and hardwood hold different amounts.
- The waste allowance is not a fixed rule. It depends on layout, plank length and installer skill.
- The price is your own input and the cost excludes underlayment, trim, adhesive, removal and labor.
- Manufacturers may set their own rules for installation and for how much to order, so check the product guide.
Frequently asked questions
How do I calculate how much flooring I need?
Multiply the room length by its width in feet to get square feet, then add 10 percent for waste. A 15 ft by 12 ft room is 180 sq ft, so you would buy about 198 sq ft.
How much waste should I allow for flooring?
Ten percent is a common starting point for a straight layout. Diagonal, herringbone and small, cut-up rooms need more.
How many boxes of flooring do I need?
Divide the square feet you need by the coverage printed on one box and round up. The calculator does this for you.
Should I measure each room separately?
Yes, if the rooms are different sizes. Calculate each room and add them, or buy by the total area if the same product runs through more than one room.
Does this work for laminate, vinyl plank and hardwood?
Yes. Any flooring sold by the square foot works, as long as you use the coverage printed on the box.
Does the cost include installation?
No. The cost is material only, based on whole boxes. Underlayment, trim, adhesive and labor are not included.
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Last updated: November 2026