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Laminate flooring calculator

Work out how many packs of laminate flooring to buy for your room. You get the number of whole packs with waste included, then the underlay rolls, the length of scotia or beading, and the expansion gap to leave.

Packs of laminate flooring and a roll of underlay on the floor of an empty room

Wall to wall at the longest point.

On the pack. Packs run from about 1.3 to 2.2 m², so check yours.

On the roll label. 10 m² is common.

doorways
Your result

Packs of laminate

11

22 m² in 11 packs, 10% waste allowed

Floor area
20 m²
Area with 10% waste
22 m²
Laminate you will have
22 m²2 m² more than the floor
Underlay rolls
210 m² each, for 20 m² of floor
Scotia or beading
17.3 medge of the room minus doorways
Expansion gap
10 mmat every wall and fixed object
  • Leave a 10 mm gap round the edge of the floor so it can expand. Do not fix the boards down. Your pack's own instructions override this.
  • Pack size varies by brand, from about 1.3 to 2.2 m². Use the figure printed on your pack.

Add this to your project shopping list, then print it or take it to the merchant.

Open shopping list

How to use the laminate flooring calculator

  1. Type in the room length and width, wall to wall. Switch on L-shaped room or alcove if you need to add more areas.
  2. Read Area in one pack from the label on the pack and type it in. Packs run from about 1.3 to 2.2 m², so don't guess.
  3. Choose how you will lay it: a plain room (5% waste), a usual room (10%), or diagonal or lots of corners (15%).
  4. Leave Also work out underlay and scotia on. Enter the underlay roll size and your doorways.
  5. Tap Add to shopping list to keep the result, or Share link to send it to someone.

Why use this calculator

It works from your pack, not a guess. Laminate is sold in packs, and every brand puts a different amount in each one, from about 1.3 m² to 2.2 m². The calculator rounds up to whole packs from the area printed on yours.

It adds the waste for you. 10% is the usual allowance for cuts. A plain, rectangular room can do with 5%, and a diagonal layout needs more.

It covers everything on the list: underlay rolls, scotia or beading for the edges, door bars, and the expansion gap. It also shows the working for each step.

How we worked it out

Your numbers, step by step. This updates as you change the calculator.

  1. Floor area = 5 m × 4 m = 20 m²
  2. Add 10% for cuts: 20 m² × 1.1 = 22 m²
  3. Packs = 22 m² ÷ 2 m² per pack, rounded up = 11 packs (22 m²)
  4. Underlay = 20 m² ÷ 10 m² per roll, rounded up = 2 rolls
  5. Edge of the room = 18 m
  6. Scotia or beading = 18 m − 1 doorway × 0.762 m = 17.24 m
  7. Leave a 10 mm expansion gap at every wall, pipe and doorframe. Skirting or scotia covers it.

The formula

  • Floor area: length × width, added up for each area.
  • Area with waste: floor area × (1 + waste). Waste is 5%, 10% or 15% depending on the layout you pick.
  • Packs: area with waste ÷ m² per pack, rounded up.
  • Underlay: floor area ÷ roll size, rounded up. No waste is added.
  • Scotia or beading: the distance round the room, minus the doorways, rounded up to 0.1 m.

A 5 m by 4 m room is 20 m². With 10% waste that is 22 m². With 2.0 m² packs, that is 22 ÷ 2.0 = 11 packs. For a 10 m² underlay roll, 20 ÷ 10 = 2 rolls. The edge is 18 m, minus a 762 mm doorway, so 17.3 m of scotia.

What we assume

  • Waste: 5% for a plain room, 10% for a usual room, 15% for diagonal or lots of corners. These are rules of thumb, not figures from one manufacturer.
  • Pack size: there is no standard. The calculator starts at 2.0 m² as a placeholder. Packs we looked at run from 1.31 to 2.22 m², so type in the figure from yours.
  • Underlay roll: 10 m², the common size for laminate and wood underlay. Foam rolls are often 15 m². Change it to match your roll.
  • Expansion gap: 10 mm at every wall and fixed object. This follows one manufacturer’s fitting instructions and other makers may differ. Follow the instructions in your pack.
  • Doorways: 762 mm wide, the most common internal door width in England and Wales. Each extra area joins the main room along its shorter side, which comes off the scotia length.
  • Trims: one threshold or door bar for each doorway.

Tips

  • Read the fitting instructions in the pack before you start. Some makers ask you to leave the packs in the room for a while first.
  • Always check the maker's own instructions. The expansion gap and the underlay they ask for come before anything on this page.
  • Keep your receipt and ask the shop whether unopened packs can be returned. That makes it safer to round up.
  • Don't forget doorways. Where laminate meets another floor, you need a threshold or door bar. Floors usually need a gap or joint between rooms too, so check your pack.
  • Not sure of the room's size? Use the square metre calculator for odd shapes. If you are comparing floors, the carpet calculator works out the carpet for the same room.

FAQs

How much laminate flooring do I need for a 5 m by 4 m room?
22 m² with the usual 10% waste, which is 11 packs if each pack covers 2.0 m². The room itself is 20 m². Use the area on your own pack, because it changes the number of packs.
How much extra laminate should I buy for waste?
Allow 10% for a usual room, 5% for a plain rectangular one and 15% for a diagonal layout or a room with lots of corners. For the 5 × 4 m room with 2.0 m² packs, that is 11, 11 and 12 packs.
How many packs of laminate do I need?
Divide the area, including waste, by the m² on one pack, then round up. A 4 m by 3.5 m room is 14 m². With 10% waste that is 15.4 m², and with 2.22 m² packs that is 7 packs.
How much underlay do I need for laminate flooring?
Enough to cover the whole floor, with no waste added. Rolls of 10 m² are common, so a 20 m² room needs 2 rolls. A 21 m² room needs 3 rolls, because 2.1 rounds up.
How do I work out laminate for an L-shaped room?
Split the room into rectangles, work out the area of each, and add them. A 4 × 3 m room with a 2 × 1.5 m alcove is 15 m². The calculator lets you add up to three areas.
How big should the expansion gap be?
Leave 10 mm at every wall, pipe and doorframe. The floor needs room to expand and shrink, and skirting or scotia hides the gap. Your pack's own instructions override this, so follow them.

Last reviewed: 6 November 2026 · How we calculate · Report an error