How much flooring do I need for a room?
Room area plus 10% for cuts — and the expansion gap and last-row rip that the area alone never tells you about. Coverage for every room size.
A 12' × 14' room takes 29 rows of 5" board, covering 168 ft² before waste.
The last row rips down to 3", and 1/2" of expansion gap is left at each wall — the floor is not supposed to touch them.
How that is worked out
- Take the expansion gap off each side first: 144" − 2 × 1/2" = 143" for the boards to fill.
- Each row covers the board's face width, so 143" ÷ 5" rounds up to 29 rows.
- The last row rarely lands on a full board. Here it ripped to 3".
Rows and last-row rip, 5" board, 1/2" expansion gap
| Room | Floor area | Rows | Last row rip | Buy with 10% waste |
|---|---|---|---|---|
| 10' × 12' | 120 ft² | 24 | 4" | 132 ft² |
| 12' × 12' | 144 ft² | 29 | 3" | 159 ft² |
| 12' × 14' | 168 ft² | 29 | 3" | 185 ft² |
| 12' × 16' | 192 ft² | 29 | 3" | 212 ft² |
| 14' × 16' | 224 ft² | 34 | 2" | 247 ft² |
| 16' × 20' | 320 ft² | 39 | 3" | 352 ft² |
Worth knowing
- The expansion gap is not optional. Wood and laminate both swell across their width with humidity, and a floor fitted tight to the walls has nowhere to go but up — it buckles in the middle of the room, and the fix is taking it apart.
- 10% waste suits a plain rectangular room. Diagonal layouts want 15%, and a room with lots of doorways, closets and jogs wants more, because each one costs a cut.
- Balance the first and last rows. If the last row would rip to a sliver, take the same amount off the first row instead so both sides are the same — a 1" strip along one wall reads as a mistake, two 3" rows read as a plan.
- Buy it all in one order, from one batch. Wood flooring varies in colour between runs, and laminate patterns get revised.
Work out your own numbers
- Flooring and decking layout
How many rows, how wide to rip the first one, and where the end joints fall so they never line up.
- Tile layout
Full tiles across the middle and a sized cut tile at every edge, centred or started from one wall.
- Baseboard calculator
Linear footage of flat trim for a room from its perimeter and its doorways, with a waste allowance.
Related questions
- How much extra flooring should I buy?
- 10% over the room's square footage for a straight layout in a simple room, 15% for a diagonal, and more for rooms cut up with closets and doorways. Order it all at once — colour and pattern vary between production runs, and a box bought later to finish a room may not match.
- How big should the expansion gap be?
- About 1/2" at every wall, hidden under the baseboard or shoe molding. It is there because the floor swells across its width with humidity, and a floor with nowhere to expand lifts off the subfloor. Check the manufacturer's figure — some wide-plank and laminate products want more.
- Should the first and last row be the same width?
- Ideally yes, or close to it. Lay the room out before you start: if starting with full boards leaves a 1" sliver at the far wall, rip the first row down so both edges come out around half a board. Nobody notices two matching narrow rows; everybody notices one.