Flooring Calculator: Square Feet, Boxes and Cost

How to work it out

Measure each room at its longest and widest points. Split L-shaped rooms into two rectangles.
Add closets and hallways that get the same floor as their own areas.
Choose the extra to allow. Around 10% is common for a straight layout, more for diagonal or herringbone.
Enter how much one box covers, printed on the box, to see how many boxes to buy.

How much extra to allow

Layout	Common extra
Straight layout, simple room	About 10%
Diagonal layout	About 15%
Herringbone or chevron	15% or more

These are common starting points. Your site, climate and supplier may call for something different.

Cost is for whole boxes

Flooring is sold in whole boxes, so the cost shown is for the boxes you buy, not just the square feet you need. Keep any spare boxes for future repairs.

Before you lay it

Many floors need to sit in the room for a while before fitting, and most need an expansion gap at the walls. Follow the maker's instructions for your floor.

Common questions

How do I calculate how much flooring I need?

Multiply length by width for each room, add them up, then add 10% or so for cuts. Divide by the square feet in one box and round up to whole boxes.

How many boxes of flooring do I need for 500 sq ft?

With 10% extra that is 550 sq ft. With boxes of 20 sq ft, that is 27.5, so 28 boxes. Check the coverage on your box.

Does this work for laminate, vinyl and hardwood?

Yes. The area maths is the same for any floor sold by the box. Only the box coverage and the extra you allow change.

Doing this job for a customer? Turn your numbers into a free written estimate on QuoteToPaid.

Flooring calculator