How this calculator works. Boxes = area × (1 + waste) ÷ box coverage, rounded up. Waste follows flooring-industry practice: 8% for straight installs, 12% for diagonal layouts or chopped-up floor plans with closets and angles. The perimeter figure is your shopping number for quarter-round or wall base and for counting transition strips at doorways.
How many boxes of flooring?
Plank flooring is bought by the box and wasted at the ends: every row's last plank gets cut, the offcut only starts the next row if it's long enough (12" minimum for most products), and a few planks per job arrive chipped or warped. That's the 8% — it isn't optional padding. Floating floors also want leftovers for the future: a plank that takes a dog-scratch or water damage can be swapped, but only with matching material from the same production batch.
Direction affects quantity less than looks, but diagonal installs genuinely consume more — every wall becomes an angled cut with an unusable triangle offcut. If you're going diagonal for the drama, budget the 12%.
Don't forget the edges
| Item | How to count |
|---|---|
| Underlayment | Same sq ft as floor (skip if attached to planks) |
| Quarter-round / shoe molding | Room perimeter, minus doorways |
| Transition strips | One per doorway, by type (T-mold, reducer, threshold) |
| Expansion gap spacers | One pack per job — 1/4"–3/8" gap at every wall |
Buying tips
Buy all boxes at once and check lot numbers match — wood-look prints repeat and colors shift between runs. Let the boxes acclimate in the room 48 hours before installing (real wood especially). And keep one unopened box after the job: it's your repair kit for the decade.
Common questions
Does the box coverage include waste?
No — the carton states net coverage. Your order = room area + waste factor, which is exactly what this calculator adds before dividing by box coverage.
Which direction should planks run?
Convention: parallel to the longest wall or the main light source, and along the hallway's length. In doubt, long direction of the space — it visually stretches the room.
Do I need underlayment under vinyl plank?
Usually not if the plank has an attached pad; check the spec. Over concrete, you may still need a vapor barrier even with attached pad — the product sheet rules.
Can plank flooring go over existing tile?
Floating floors usually can, if the tile is flat (within 3/16" over 10 ft) and grout lines are shallow or skim-coated. Solid hardwood nail-down cannot — it needs a wood subfloor.