Flooring Calculator: How Many Packs Do I Need?
Work out how many packs of laminate, wood or click vinyl flooring you need for a room, plus the underlay, damp-proof membrane, beading and door bars to go with them.
No sign-up required. Free to use, with every formula shown on this page. Last reviewed October 2026.
Work out your flooring
Flooring Calculator
Work out how many packs of laminate, wood or click vinyl flooring a room needs, and the underlay, beading and door bars to go with them.
1 The room
Floor size: length × widthSplit an L-shaped room into two rectangles. Measure wall to wall; don't take off the expansion gap.
Areas to leave out2 The flooring
Type of flooring Laying patternIt's on the pack or the shop's page, often as "2,22 m² per pack".
3 Underneath and edges
What's the floor underneath?4 Prices (optional)
Add the prices you've seen to get a total. Leave any box empty to skip it.
Flooring you need
0 packs
Floor area
0 m²
Perimeter
0 m
Underlay
–
What you'll need
Breakdown
| Area | Size | m² |
|---|
How it's worked out: packs = floor area × (1 + extra %) ÷ the m² in a pack, rounded up. Underlay = area + 5% ÷ the m² in a roll. Damp-proof membrane = area + 10% for 200 mm overlaps. Beading = (perimeter − 0,8 m for each doorway) + 10% ÷ the length. One door bar per doorway. Extra rectangles are assumed to join the room along their width when the perimeter is worked out; type your own if the room is a different shape.
Estimates only. Pack sizes vary: check the m² on the pack you're buying. Leave the expansion gap the maker asks for (usually 8–12 mm) round the edges, and buy all your packs from the same batch.
How it works
Area, extra and packs
Flooring is sold in packs that each cover a set number of m², so the calculator works out the floor area, adds a little for cuts and spares, and rounds up to whole packs. The sources and assumptions behind it are on our How we calculate page.
Measure the floor
Measure wall to wall and multiply length × width. Split an L-shaped room into rectangles and take away anything the floor won’t go under, such as kitchen units or a fitted bath. Don’t take off the expansion gap: it’s too small to matter.
Add the extra and round up
Add 10% for cuts and a few spares, or 15% for diagonal and herringbone floors, which need more cuts. Divide by the m² on the pack and round up: 14 m² plus 10% is 15.4 m², which is 8 packs of 2 m².
Underneath and the edges
Underlay is counted by the roll and a damp-proof membrane goes on concrete floors. Round the edges, beading covers the expansion gap if the skirting stays on: the perimeter less the doorways. Each doorway gets a door bar.
Examples
How many packs of flooring do I need?
The same calculator, a few common rooms. As a rule of thumb, buy about 10% more than the floor area, and keep a spare pack for repairs.
Illustrative only, from the calculator above. 10% extra for straight laying, 15% for herringbone; underlay in 10 m² rolls (none for click vinyl with underlay attached); beading in 2.4 m lengths for the perimeter less 0.8 m per doorway, plus 10%. Check the m² on the pack you’re buying.
Tips
Before you lay the floor
A floor lasts longer when the boards have settled, the floor underneath is flat and dry, and the edges can move.
Let the boards settle
Leave the packs flat in the room for at least 48 hours before fitting (longer for wood) so they adjust to the room’s temperature and humidity. Check every pack has the same batch number, and mix boards from several packs as you lay them.
Prepare the floor underneath
The floor needs to be flat, clean and dry. On concrete, lay a damp-proof membrane (or an underlay with one built in), and check a new screed is dry. Click vinyl usually needs only a thin underlay, and many boards have it attached.
Leave an expansion gap
Floating floors move with the seasons, so leave the gap the maker asks for, usually 8–12 mm, round every wall, pipe and door frame. Cover it with beading, or take the skirting off and refit it over the floor. Use a door bar at each doorway.
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Common questions
Frequently asked questions about how much flooring you need
Common questions about packs, extra, underlay, beading and the expansion gap.
How much flooring do I need?
Multiply the room’s length by its width to get the area in m², take away anything the floor won’t go under, then add 10% for cuts and spares. A 4 × 3.5 m room is 14 m², so buy 15.4 m²: 8 packs of 2 m². The calculator works it out for your own room, including L-shapes.
How much extra flooring should I buy?
About 10% for boards laid straight, and 15% for diagonal or herringbone floors, which need more cuts at the edges. Buy a little more for an awkward room with lots of corners, and keep a spare pack for repairs.
How many m² are in a pack of laminate?
Usually between 1.5 and 2.5 m², often around 2 m² for laminate, 2.2 m² for click vinyl and 1.5–2 m² for engineered wood. It’s printed on the pack and the shop’s page, so check it before you work out how many packs to buy.
How much underlay do I need?
The floor area plus about 5%, in rolls. Most laminate and vinyl underlay comes in 10 m² rolls, so a 14 m² room needs 2 rolls. Click vinyl often has underlay attached, in which case don’t add another layer.
Do I need a damp-proof membrane under laminate?
On a concrete floor, yes: lay a damp-proof membrane with the joins overlapped by about 200 mm, or use an underlay with a built-in DPM. On wooden floorboards you don’t need one, and it can trap moisture in the boards.
How much beading do I need?
Measure round the room, take off the doorways, and add 10%. Beading (scotia) usually comes in 2.4 m lengths, so a 4 × 3.5 m room with one doorway needs 7 lengths. If you take the skirting off and refit it over the floor, you don’t need beading.
How big should the expansion gap be?
Usually 8–12 mm round the edges for laminate and wood, and smaller for click vinyl: check the maker’s instructions. Leave it at every wall, pipe and door frame, and don’t fill it; beading or skirting covers it.
Are the results exact?
No. They are estimates: how much flooring you use depends on the room’s shape, the board length and how you lay it. The calculator adds the extra you choose and rounds up to whole packs and rolls.