How Much Flooring Do I Need? A Simple m² Calculator Guide

Ordering flooring is the one part of a renovation where being slightly wrong costs real money. Too little and you're chasing the last pack of a discontinued batch six weeks into the job. Too much and you're storing twelve unwanted boards in the loft forever.

This guide walks through how to measure a room for laminate, LVT or slat wall panels — including the waste percentages that fitters actually use, the awkward shapes most online calculators get wrong, and a worked example you can copy.

What you'll need

• A 5m tape measure (avoid laser distance meters for irregular rooms — they're easy to mis-aim).
• A pencil.
• Paper, ideally graph paper.
• A calculator or your phone.

That's it. The whole job should take 15–30 minutes per room.

Step 1: Draw the room

Sketch the room as seen from above. Don't worry about scale — just shape.

Include every wall, the door opening (where the floor finishes or carries through to a hallway), any chimney breast or alcoves, wall corners that aren't 90° (older properties have a lot of these), built-in furniture you'll fit around (kitchen islands, fitted wardrobes), and built-in furniture you'll fit under (lift bath, fitted wardrobes you'll keep).

Step 2: Measure every wall

Run the tape along each wall, recording the dimension in metres to two decimals. So 4,250mm is 4.25m.

Measure to the plaster, not the skirting — if you're removing skirting before fitting, the floor runs to the plaster. If you're leaving skirting in place, the floor runs to the skirting and you'll lose 15–25mm each side.

Write each dimension on the relevant wall in your sketch.

Step 3: Treat the room as rectangles

The fastest reliable method for an awkward UK room is to divide it into rectangles, calculate each, then add them together.

Most rooms — even with chimney breasts and bay windows — can be broken into two or three rectangles.

For each rectangle:

Area (m²) = length (m) × width (m)

Add the rectangles together for the total. Then subtract any built-in furniture you'll fit around.

Worked example: a Victorian terrace living room

Sketch:

• Main room: 4.20m × 3.80m
• Chimney breast (subtract): 1.40m × 0.30m
• Alcove 1 (add — running floor into it): 0.80m × 0.45m
• Alcove 2 (add): 0.80m × 0.45m

Calculation:

• Main room: 4.20 × 3.80 = 15.96 m²
• Chimney breast: 1.40 × 0.30 = 0.42 m² (subtract)
• Alcove 1: 0.80 × 0.45 = 0.36 m²
• Alcove 2: 0.80 × 0.45 = 0.36 m²

Total: 15.96 − 0.42 + 0.36 + 0.36 = 16.26 m²

Step 4: Add waste

Flooring waste comes from three places:

1. Cuts at the perimeter where boards don't end neatly at a wall.
2. Cuts around obstacles (sockets, chimney breast corners, kitchen islands).
3. Pattern matching when starting each new row.

Use these percentages:

• Straight plank laminate or LVT in a rectangular room: +5%.
• Straight plank in a room with chimney breast, alcoves, or angled walls: +8–10%.
• Herringbone laminate: +12–15%.
• Stair flooring: +15–20%.
• Bay windows or curved walls: +15%.

For our worked example, 16.26 m² × 1.10 (10% waste for the chimney breast and alcoves) = 17.89 m², round up to 18 m².

Step 5: Check pack sizes

Laminate and LVT ship in packs covering a specific m² — usually 1.50–2.40 m² depending on plank size. You can't order half packs.

Take your total and round up to the nearest pack.

For our example, if Accent's range ships in 2.40 m²/pack: 18 ÷ 2.40 = 7.5 packs → order 8 packs = 19.20 m².

The extra is your insurance pack: it lives in the garage for the inevitable future repair.

Step 6: Don't forget transitions and trims

• Threshold strips (T-bars): one per doorway, plus any room-to-room transition in continuous flooring.
• Scotia (quarter-round) bead: if you're not removing skirtings, you'll need scotia along every wall the floor terminates against. Measure perimeter (sum of all wall lengths) and add 10% waste.
• Underlay: rolls cover a specific m² — typically 8.4 m² per roll for foam, 10 m² for foil-backed. Round up.
• DPM: if going over concrete, separate or built into the underlay.

Measuring stairs

Stairs are awkward and easy to under-order. The basic principle: each step is one tread + one riser, plus a small nosing overlap.

• Tread (top of step): typical UK depth 220–280mm. Measure tread depth × width.
• Riser (vertical face): typical 180–200mm. Measure riser height × width.
• Plus 50mm for the nosing curve wrapping over the front of each tread.

A typical 13-stair flight in a UK semi takes around 4–5 m² of laminate plus the appropriate stair nosings.

For laminate on stairs, always buy from the same batch as the surrounding floor for colour consistency, and order 20% waste because cuts on stairs go wrong more often.

Measuring for wall panels

Slat wall panels are sold per panel and per m². Each panel typically covers 290 × 2,400mm (0.696 m²).

To calculate panels for a feature wall:

1. Measure wall width in metres.
2. Measure wall height in metres.
3. Multiply: width × height = wall area in m².
4. Add 10% for cutting waste around sockets and trimming.
5. Divide by panel m² to get the number of panels (round up to whole panels).

Example: 3.2m × 2.4m living room feature wall

• 3.2 × 2.4 = 7.68 m²
• 7.68 × 1.10 = 8.45 m²
• 8.45 ÷ 0.696 = 12.14 → order 13 panels.

For full-height ceiling installations or where the wall has heavy obstructions (TV mount, sockets, fire), use 15% waste.

Common measuring mistakes

1. Measuring once. Always twice. The dimensions are how much money you spend.
2. Forgetting the chimney breast. Old terraces have one in every room.
3. Measuring to the skirting when you'll remove it. Adds error of up to 50mm per wall.
4. Forgetting the bay. Bays add real m² and they're easy to miss.
5. Forgetting underlay. It's a separate line item — easy to leave off.
6. Ordering the exact m² with no waste. Even the best calculator can't predict a tile snapping at a critical cut.
7. Forgetting transition strips. Always one per doorway, often more.

When to ask a fitter to measure

If your room has any of the following, get a flooring fitter or surveyor to measure for you. Most do it free as part of a quote:

• A bay window with curved walls.
• A staircase you're flooring.
• Walls that aren't square (any pre-1950 property is worth a check).
• A herringbone install, where the pattern interacts with every edge.
• Underfloor heating you're installing under the floor.

A 30-minute survey by a fitter is the cheapest insurance you can buy.

Quick reference table

Room type	Waste %	Notes
Simple rectangular bedroom	+5%	Straight plank
Living room with chimney breast	+8–10%	Straight plank
Herringbone any room	+12–15%	Pattern adds waste
Hallway, narrow	+10%	Many short cuts
Stairs	+15–20%	Cuts go wrong
Kitchen with island	+10%	Cuts around units
Bay window	+15%	Angled cuts
Feature wall (slat panels)	+10%	Sockets and trims
Full-height wall + TV cut-out	+15%	Large cut-out

FAQs

How much extra should I order in case of a future repair? At least one full pack. Manufacturers discontinue ranges; matching boards five years on is hard.

Can I return unopened packs? Most retailers, including Accent, accept unopened, undamaged packs within their stated return period. Always check before ordering.

Should I order extra underlay too? Yes — 10% extra. It's cheaper than ordering a single roll separately later.

How do I measure an L-shaped room? Split it into two rectangles. Calculate each separately, then add.

Do I need to acclimatise the boards before measuring? No, but you must acclimatise them in the room 48 hours before fitting. This doesn't affect quantities.

What to do next

1. Sketch your room on graph paper.
2. Measure every wall twice.
3. Calculate area as rectangles, subtract obstacles.
4. Add the right waste percentage for your pattern and room shape.
5. Round up to whole packs.
6. Add underlay, threshold strips and scotia in the same order.

Order free flooring samples → /collections/samples