The Quick Answer
To work out how much flooring you need: measure your room’s length and width in metres, multiply them together to get the area in square metres (m²), then add 10% for wastage. That gives you the total amount of flooring material to buy. For a more precise figure, use our free flooring calculator which handles all the maths instantly.
But if you have an L-shaped room, a room with alcoves, or you are planning a herringbone pattern, the calculation is a bit more involved. This guide walks you through every scenario you are likely to encounter in a UK home, with worked examples for the most common room sizes.
Step 1: Measure Your Room
Tools You Need
Before you start, gather these items:
- Tape measure — a 5-metre or 8-metre retractable tape is ideal. Laser distance measurers are even more accurate and cost as little as £20 from Screwfix or Toolstation.
- Pen and paper — sketch the room shape and note measurements as you go. A rough floor plan helps enormously.
- Calculator — or use the calculator on your phone.
Measuring a Rectangular Room
Most bedrooms, living rooms, and dining rooms in UK homes are roughly rectangular. Measure the longest wall from one end to the other — this is your length. Then measure the perpendicular wall — this is your width. Always measure at floor level, not at skirting board height or waist height, as walls can lean slightly and skirting boards add thickness.
Take each measurement at two or three points along the wall and use the largest figure. UK homes, especially older properties built before the 1960s, rarely have perfectly straight walls. Using the largest measurement ensures you have enough flooring to cover the full area.
Record measurements in metres and centimetres (e.g. 4.35m, not “about 4 and a half metres”). The more precise your measurements, the more accurate your flooring order will be.
Measuring an L-Shaped Room
L-shaped rooms are common in UK homes, particularly in living-dining areas and extensions. The trick is to split the L into two separate rectangles:
- Stand in the room and identify where the L changes direction.
- Imagine a straight line across the room at this point, dividing the L into two rectangles.
- Measure the length and width of Rectangle A.
- Measure the length and width of Rectangle B.
- Calculate the area of each rectangle (length × width) and add them together.
For example, if Rectangle A is 5m × 3m (15 m²) and Rectangle B is 3m × 2.5m (7.5 m²), the total floor area is 22.5 m².
Measuring Rooms with Bay Windows
Bay windows add extra floor area that is easy to forget. Measure the bay as a separate rectangle (or trapezoid for angled bays) and add it to the main room area. For a rectangular bay, measure its depth from the main wall line and its width. For an angled bay, measure the widest point and the depth, then multiply and reduce by about 15% to account for the angled walls.
Measuring Rooms with Alcoves and Chimney Breasts
Victorian and Edwardian terraced houses commonly have chimney breast recesses that create alcoves on either side. Measure the full room including the chimney breast area, then subtract the chimney breast footprint if you will not be flooring over it (rare — most people floor the entire room). In practice, it is easier and safer to measure the maximum room dimensions and accept a small amount of extra material as part of your wastage allowance.
Converting Feet to Metres
If your tape measure shows feet and inches, you need to convert to metres since all UK flooring is sold in metric measurements. Use these common conversions:
| Feet | Metres | Common Room Type |
|---|---|---|
| 8 ft | 2.44m | Small bedroom |
| 9 ft | 2.74m | Single bedroom |
| 10 ft | 3.05m | Double bedroom |
| 11 ft | 3.35m | Master bedroom |
| 12 ft | 3.66m | Living room |
| 13 ft | 3.96m | Large living room |
| 14 ft | 4.27m | Dining room |
| 15 ft | 4.57m | Large reception |
| 16 ft | 4.88m | Open plan |
| 20 ft | 6.10m | Large open plan |
The formula is: feet × 0.3048 = metres. For feet and inches, convert the inches to a decimal first (e.g. 10ft 6in = 10.5ft = 3.20m).
Step 2: Calculate Floor Area
Once you have your measurements, calculating the floor area is straightforward:
Floor Area (m²) = Length (m) × Width (m)
For example:
- A room measuring 4.5m × 3.2m = 14.40 m²
- A room measuring 5.0m × 4.0m = 20.00 m²
- A room measuring 3.6m × 3.0m = 10.80 m²
Multiple Rooms
If you are fitting the same flooring through several rooms (common for hallways and adjoining rooms), calculate each room separately and add them together. Include doorway areas in the measurement of the room they connect to. For continuous flooring through multiple rooms, it is important to buy the entire quantity from the same batch to avoid colour variations.
Step 3: Add Wastage Allowance
Wastage is the material lost to cutting, offcuts, and the occasional damaged piece. No flooring installation uses 100% of the material. The wastage percentage depends on the room shape and the laying pattern:
| Scenario | Wastage % | Reason |
|---|---|---|
| Rectangular room, straight lay | 10% | Standard edge cuts and end-of-row offcuts |
| L-shaped room | 12–15% | Additional cuts where the L changes direction |
| Room with alcoves or bay window | 12–15% | Extra trimming around irregular shapes |
| Herringbone pattern | 15–18% | Angled cuts on every row and at edges |
| Chevron pattern | 18–20% | All planks cut at angles, more offcuts |
| Diagonal lay | 15–18% | Angled cuts along all walls |
| First-time DIY installer | Add extra 5% | Account for learning mistakes |
To apply the wastage: multiply your floor area by the wastage percentage and add it to the original area. For example, a 15 m² room with 10% wastage = 15 + (15 × 0.10) = 15 + 1.5 = 16.5 m² total flooring needed.
Step 4: Convert to Packs or Rolls
Laminate and Engineered Wood (Packs)
Laminate and engineered wood are sold in packs with a stated coverage in m². Common UK pack sizes include 1.99 m², 2.13 m², and 2.22 m². Divide your total area (including wastage) by the pack coverage, then round up to the next whole number.
Packs needed = Total area ÷ Pack coverage (rounded up)
Carpet (Rolls)
Carpet is sold from rolls with a fixed width (4m or 5m in the UK). You buy a length cut from the roll. If your room is narrower than the roll width, one strip covers the room. If wider, you need two strips with a join. The length you need is the room length plus a few centimetres for trimming.
Vinyl (Rolls or Packs)
Sheet vinyl comes in rolls like carpet (typically 2m, 3m, or 4m wide). Click-lock LVT comes in packs similar to laminate. The calculation method depends on which type you are buying.
Underlay
Underlay rolls are typically 15m × 1.37m, covering approximately 15 m² per roll. Divide your total area by 15 to find how many rolls you need. See our underlay calculator for precise calculations.
Worked Examples for Common UK Room Sizes
Here are complete worked examples for the most common room sizes people search for. All examples use 10% wastage and standard 1.99 m² laminate packs.
How Much Flooring for a 10x10 Room
A 10x10 foot room is approximately 3.05m × 3.05m (a typical UK double bedroom).
- Floor area: 3.05 × 3.05 = 9.30 m²
- Plus 10% wastage: 9.30 + 0.93 = 10.23 m²
- Laminate packs (1.99 m²): 10.23 ÷ 1.99 = 5.14 → 6 packs
- Carpet (4m roll): 3.05m length → order 3.2 linear metres
- Estimated cost: £82–£256 (laminate) or £62–£410 (carpet)
How Much Flooring for a 12x12 Room
A 12x12 foot room is approximately 3.66m × 3.66m (a typical UK living room).
- Floor area: 3.66 × 3.66 = 13.40 m²
- Plus 10% wastage: 13.40 + 1.34 = 14.74 m²
- Laminate packs (1.99 m²): 14.74 ÷ 1.99 = 7.41 → 8 packs
- Carpet (4m roll): 3.66m length → order 3.8 linear metres
- Estimated cost: £118–£369 (laminate) or £88–£590 (carpet)
How Much Flooring for a 15x12 Room
A 15x12 foot room is approximately 4.57m × 3.66m (a large UK living room or master bedroom).
- Floor area: 4.57 × 3.66 = 16.73 m²
- Plus 10% wastage: 16.73 + 1.67 = 18.40 m²
- Laminate packs (1.99 m²): 18.40 ÷ 1.99 = 9.25 → 10 packs
- Carpet (5m roll): 4.57m length → order 4.7 linear metres (use 5m roll since room is 3.66m wide)
- Estimated cost: £147–£460 (laminate) or £100–£736 (carpet)
How Much Flooring for a 20x15 Room
A 20x15 foot room is approximately 6.10m × 4.57m (a large open-plan area).
- Floor area: 6.10 × 4.57 = 27.88 m²
- Plus 10% wastage: 27.88 + 2.79 = 30.67 m²
- Laminate packs (1.99 m²): 30.67 ÷ 1.99 = 15.41 → 16 packs
- Carpet (5m roll): will need two strips joined, order 12.2 linear metres from a 4m roll, or 6.2 linear metres from a 5m roll
- Estimated cost: £245–£767 (laminate) or £184–£1,227 (carpet)
How Much Flooring for an L-Shaped Room
Example: An L-shaped living-dining room where Rectangle A is 5m × 4m and Rectangle B is 3m × 2.5m.
- Area A: 5.0 × 4.0 = 20.00 m²
- Area B: 3.0 × 2.5 = 7.50 m²
- Total floor area: 20.00 + 7.50 = 27.50 m²
- Plus 15% wastage (L-shaped): 27.50 + 4.13 = 31.63 m²
- Laminate packs (1.99 m²): 31.63 ÷ 1.99 = 15.89 → 16 packs
- Estimated cost: £253–£791 (laminate)
Flooring Quantities by Room Type
UK homes follow fairly predictable room sizes. Here is a quick-reference table showing typical flooring requirements for standard UK rooms, including 10% wastage:
| Room | Typical Size | Area (m²) | With 10% Wastage | Laminate Packs* |
|---|---|---|---|---|
| Single bedroom | 2.4m × 3.0m | 7.20 | 7.92 | 4 |
| Double bedroom | 3.0m × 3.6m | 10.80 | 11.88 | 6 |
| Master bedroom | 3.6m × 4.2m | 15.12 | 16.63 | 9 |
| Living room | 4.0m × 5.0m | 20.00 | 22.00 | 12 |
| Kitchen | 3.0m × 3.5m | 10.50 | 11.55 | 6 |
| Hallway | 1.2m × 5.0m | 6.00 | 6.60 | 4 |
| Bathroom | 2.0m × 2.5m | 5.00 | 5.50 | 3 |
| Open plan living-dining | 5.0m × 7.0m | 35.00 | 38.50 | 20 |
*Based on 1.99 m² per pack, rounded up
Pack Sizes by Flooring Type
Different flooring types are packaged differently. Understanding how your chosen flooring is sold helps you convert your area calculation into the correct order quantity.
Laminate Flooring Packs
Laminate is sold in sealed packs containing a fixed number of planks. The pack states the coverage in m². Common UK pack sizes are 1.72 m², 1.99 m², 2.13 m², and 2.47 m². Divide your total area by the pack coverage and round up. Our laminate flooring calculator handles this automatically.
Vinyl and LVT Packs
Click-lock LVT comes in packs similar to laminate, typically covering 2.0–2.5 m² per pack. Sheet vinyl is sold by the linear metre from rolls that are 2m, 3m, or 4m wide. For sheet vinyl, you need to order a length that covers your room’s longest dimension. Our vinyl flooring calculator works out both types.
Carpet Rolls
Carpet is sold by the linear metre from rolls of fixed width (4m or 5m). Order enough length to cover the room plus 10cm for trimming. If the room is wider than the roll, two strips are needed with a join. Our carpet calculator handles strip calculations and join placement.
Hardwood and Engineered Wood Packs
Similar to laminate, hardwood and engineered wood come in packs with stated coverage. Pack sizes vary more widely — from 1.2 m² to 3.0 m² depending on plank dimensions. Check the pack coverage before calculating quantities. Our hardwood flooring calculator covers all common pack sizes.
Common Mistakes to Avoid
These are the most frequent errors people make when calculating flooring quantities:
1. Not Allowing for Wastage
The single most common mistake. Ordering exactly the measured area guarantees you will run short. Always add at least 10% — it is far cheaper to have one extra pack than to try to order a single replacement pack weeks later (which may be from a different production batch with a slightly different shade).
2. Rounding Down Instead of Up
If the calculation says 7.1 packs, you need 8 packs, not 7. You cannot buy partial packs, and being half a pack short means an incomplete floor.
3. Forgetting Door Thresholds
Flooring extends into doorframes and under door thresholds. Include these small areas in your measurement — they add up across a whole house.
4. Measuring at Skirting Board Level
Always measure at floor level. Skirting boards, especially in older UK homes, can be 15–20mm thick, which adds 30–40mm to each dimension when measured at the wrong height.
5. Not Accounting for Room Shape
An L-shaped room, a room with a bay window, or a room with chimney breast alcoves all need higher wastage allowances than a simple rectangle. Increase your wastage to 12–15% for anything that is not a straightforward rectangle.
6. Mixing Batches
If you need 10 packs and the shop has 8 from one batch and 2 from another, the colours may not match. Always buy all your flooring from the same batch. If the shop does not have enough, ask them to order the full quantity from one batch.
Use Our Free Calculator
Rather than doing all this maths by hand, use our free flooring calculator to get instant results. Enter your room dimensions, select your flooring type, and get the exact area, pack count, and cost estimate. We also have specialist calculators for each flooring type:
Main Flooring Calculator
Quick area and cost for any flooring type
Laminate Flooring Calculator
Packs, planks, and expansion gaps
Carpet Calculator
Roll widths, strips, and joins
Vinyl & LVT Calculator
Sheet vinyl and click-lock tiles
Full Cost Estimator
Materials, fitting, and regional pricing
Underlay Calculator
Rolls, thickness, and type
Frequently Asked Questions
A 10x10 foot room is approximately 3.05m × 3.05m, giving a floor area of 9.3 m². Adding 10% wastage brings the total to 10.23 m². For laminate in standard packs of 1.99 m², you would need 6 packs.
A 12x12 foot room is approximately 3.66m × 3.66m, giving a floor area of 13.4 m². Adding 10% wastage brings the total to 14.74 m². For laminate in standard packs of 1.99 m², you would need 8 packs.
Split the L-shape into two rectangles. Measure the length and width of each rectangle separately, calculate the area of each (length × width), then add both areas together. Add 12–15% wastage for L-shaped rooms instead of the standard 10%.
For a standard rectangular room with straight-lay flooring, add 10% extra. For L-shaped rooms or rooms with alcoves, add 12–15%. For herringbone or chevron patterns, add 15–20%. First-time DIY installers should add an extra 5% on top.
Multiply feet by 0.3048 to get metres. For example, 10 feet = 3.05 metres, 12 feet = 3.66 metres, 15 feet = 4.57 metres. UK flooring is sold in metric measurements.
Calculate your total floor area including wastage, then divide by the pack coverage stated on the packaging. Always round up to the next whole pack. For example, if you need 14.5 m² and each pack covers 1.99 m², you need 8 packs.