How much flooring do I need for a 12x12 room?

A 12 x 12 ft room is 144 sq ft. With a 10% waste allowance you should plan for about 158.4 sq ft. Divide that by the coverage printed on the carton to get the number of boxes, then round up.

What waste allowance should I use?

Ten percent is a common starting point for a rectangular room. Use 15% or more for diagonal layouts, herringbone patterns, or rooms with many corners and doorways, since those produce more offcuts.

Do I need to subtract closets or cabinets?

Measure the open floor area you intend to cover. For large built-ins you can subtract their footprint, but it is usually safer to leave a small margin rather than come up short.

How do I convert square footage to boxes?

Divide your total square footage, including waste, by the coverage per box listed on the carton, then round up to the next whole box. Boxes are usually not split at the store.

Flooring Calculator

Enter the room dimensions and a waste allowance to get the square footage to order. Add the coverage per box from the carton and the calculator will also tell you how many boxes to buy, rounded up.

Flooring needed

198 sq ft

Including 18 sq ft of waste allowance.

Room area: 180 sq ft
Waste allowance: 18 sq ft
Boxes to buy: 9 boxes
Coverage per box: 24.36 sq ft

Planning note

Keep at least one spare box from the same batch for repairs. Colors can vary slightly between production runs.

How this calculator works

The calculator multiplies length by width to get the room area, adds a waste allowance, and divides by the coverage per box when you provide it.

area            = length × width
area with waste = area × (1 + waste % ÷ 100)
boxes           = round up (area with waste ÷ coverage per box)

Assumptions

Each entry is a single rectangular area. For an L-shaped room, split it into rectangles and add the results.
The waste allowance is applied to the measured area and defaults to 10%.
Box coverage is optional. Without it, the result shows square footage only.
Boxes are rounded up because flooring is sold in whole cartons.

Worked example

A 15 ft by 12 ft room is 180 sq ft. Adding 10% gives 198 sq ft. If each box covers 24.36 sq ft, then 198 ÷ 24.36 = 8.13, which rounds up to 9 boxes.

Common mistakes

Ordering the exact room area with no waste allowance.
Using the coverage per plank instead of the coverage per box.
Mixing boxes from different production batches, which can look slightly different.

Frequently asked questions

How much flooring do I need for a 12x12 room?: A 12 x 12 ft room is 144 sq ft. With a 10% waste allowance you should plan for about 158.4 sq ft. Divide that by the coverage printed on the carton to get the number of boxes, then round up.
What waste allowance should I use?: Ten percent is a common starting point for a rectangular room. Use 15% or more for diagonal layouts, herringbone patterns, or rooms with many corners and doorways, since those produce more offcuts.
Do I need to subtract closets or cabinets?: Measure the open floor area you intend to cover. For large built-ins you can subtract their footprint, but it is usually safer to leave a small margin rather than come up short.
How do I convert square footage to boxes?: Divide your total square footage, including waste, by the coverage per box listed on the carton, then round up to the next whole box. Boxes are usually not split at the store.

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Last updated: September 25, 2026