How to calculate flooring
Flooring is measured in square feet and sold by the box. Measure each room, add the areas, add waste for the pattern you are laying, then divide by the coverage printed on the box. This flooring calculator also counts the underlayment, baseboard and transitions that go with it.
To order = area x (1 + waste %)
Boxes = to order / sq ft per box, rounded up
Baseboard = room perimeters - 3 ft per doorway
Worked example: a 12 x 15 room
12 x 15 is 180 sq ft. A straight lay with 10% waste needs 198 sq ft. At 20 sq ft per box that is 9.9, so 10 boxes. Underlayment covers the 180 sq ft with 2 rolls of 100 sq ft, and the 54 ft perimeter less one 3 ft doorway leaves 51 lf of baseboard.
Waste by pattern
- Straight lay: about 10%.
- Diagonal: about 15%.
- Herringbone or chevron: about 20%.
Add more for rooms with lots of corners, closets or angled walls. For tile, use the tile calculator, which counts pieces and thinset.
Building these for a living? See Bolster for flooring contractors, or how digital takeoff and AutoCost turn measurements into priced estimates.
FAQ
How do I calculate how much flooring I need?
Multiply the length and width of each room, add the rooms together and add waste: about 10% for a straight lay, 15% for diagonal and 20% for herringbone. Divide by the square feet per box and round up.
How much extra flooring should I buy?
Plan for 10% on a straight install in simple rooms. Go to 15 to 20% for diagonal or herringbone patterns, small rooms, closets and angled walls. Keep a box back for future repairs.
How many boxes of LVP do I need?
Take the square footage with waste and divide by the coverage on the box, which is usually between 18 and 30 sq ft for LVP and laminate. 198 sq ft at 20 sq ft a box is 10 boxes.
How do I measure baseboard for a room?
Add up the perimeter of each room and take away the width of each doorway, which is about 3 ft for a standard interior door. Buy baseboard in 8 to 16 ft lengths and allow extra for corners.
Can I turn this into a flooring estimate?
Yes. Add unit prices here for a material total. In Bolster, AutoCost prices flooring, underlayment and trim with live regional costs, and the estimate turns into a proposal with upgrade options.
