Room Measurement Calculator
🇬🇧 United Kingdom version
Ordering flooring, skirting or wallpaper in the UK starts with room sizes in metres and ends with a number of boxes, packs or rolls. This version starts in metres and square metres, subtracts doors and windows from the walls, totals several rooms and turns the area you pick into boxes with a waste allowance.
Use Room Measurement Calculator online
Room Measurement Calculator
Work out floor area, wall area, perimeter and volume for every room in a project, deduct doors and windows, and turn the totals into a materials order.
United Kingdom rules and figures
- UK floor areas are normally quoted in square metres, so this version opens in metres and m² instead of feet.
- Materials starts with a pack covering 2 m² and a 10% waste allowance, both examples to replace with the figures on the pack you buy.
- The starting skirting run is the room’s perimeter in metres, before you take out gaps for doorways.
- VAT is charged at a standard 20% in the UK; use the pack price shown at the checkout for the cost line.
Sources: HMRC: United Kingdom tax authority (VAT rates) (checked 2026-11-08)
How the Room Measurement Calculator works
Rooms are treated as rectangles under a flat ceiling. The calculator holds sizes in feet internally and shows square metres and metres, so a typed 5.5 m is read as exactly 5.5 m.
floor = L × W; skirting run = 2(L + W); net wall = 2(L + W) × H − openings; boxes = ceil(area × (1 + waste) ÷ coverage)
- The two starting rooms are a 5.5 × 4.3 m living room with a 2.7 m ceiling and a 3.7 × 3.4 m bedroom. Openings begin at 0.9 × 2.03 m for doors and 1.2 × 1.5 m for the living-room windows.
- Metric input takes plain decimal numbers only. The feet-and-inches shorthand such as 12'6" is accepted when you switch Display units to feet.
- Materials starts at 10% waste and a box covering 2 m², with no price. Pick Tile 5%, Plank 10%, Diagonal 15% or Herringbone 20% for the layout you plan.
- Rooms are kept in this browser, and a deleted room goes to Recently deleted instead of vanishing.
How to use the Room Measurement Calculator
- Enter each room in metres. Type length, width and ceiling height for every room. Add room gives you another row, and an incomplete room is flagged.
- Mark doors and windows. Use the + Door and + Window buttons in a room, then give each opening a width, height and count.
- Read the room totals. On Totals you get floor, net and gross wall, ceiling, volume and the skirting run for all rooms together.
- Convert area into boxes. Open Materials, choose a surface, set the waste and the cover of one box, then add its price in pounds.
- Keep a copy. Copy summary puts the figures on your clipboard, and Export CSV saves the per-room table.
Example: Two rooms in metres, laminate in 2 m² packs
The living room has 23.65 m² of floor, 19.60 m of skirting run and 45.67 m² of net wall. The bedroom adds 12.58 m² of floor. Together the floor is 36.23 m², the skirting run 33.80 m, the net wall 81.28 m² and the volume 97.82 m³. Ten per cent waste lifts the floor to 39.85 m², so you need 20 packs of 2 m², leaving 0.15 m² spare.
When to use the Room Measurement Calculator
- Laying laminate or vinyl. Add the rooms, pick floor, and read the packs of 2 m² after the allowance for cuts.
- Buying skirting boards. Take the total perimeter in metres and divide by the length of a board, remembering to subtract doorways.
- Ordering wallpaper. Use net wall area, since openings are normally deducted for rolls, then add waste for pattern matching.
- Checking room size for a radiator. Read the volume in cubic metres as a rough input for a heating quote.
What the Room Measurement Calculator does not do
- Switching units converts the typed sizes (rounded to 4 decimals), so flipping back and forth can leave tiny rounding differences. Metric and feet-and-inches shorthand cannot be mixed: inch shorthand is read only in feet mode.
- Rooms are rectangles with flat ceilings. For an L-shape, add two rooms; sloping ceilings need an average height.
- The Materials tab prices whole units only, so the cost is units times the price you enter, with no discounts, tax or delivery. Outside the US no starting price is filled in.
- Opening areas ignore frames and reveals, and every door or window you add uses a typed size, not a catalogue size.
- Measure real rooms at several points: the tool trusts the one number you type for each side.
When something else is a better fit
- When you are estimating paint and want coats, texture and colour change built in, use the Paint Calculator.
- When you need to convert measurements between feet, metres and inches, use the Unit Converter.
- When the room is irregular or you need a scaled drawing, use a floor-plan or CAD app, or a laser measure with a sketch.
Questions about the Room Measurement Calculator
How do I enter metres?
Type plain decimals such as 5.5 in the Length, Width and Ceiling boxes. Metres are the default here, so no unit setting is needed, and the openings use metres too.
How many packs of flooring do the example rooms need?
20 packs of 2 m². The floor is 36.23 m², and 10% waste makes 39.85 m². Dividing by 2 and rounding up gives 20, which leaves 0.15 m² spare.
Should I subtract doors for paint?
Not usually. Cutting in round frames takes about as much paint as the area saved, so use the gross wall figure for paint and the net figure for wallpaper or panelling.
What does the waste figure cover?
It is a percentage added to the measured area for cuts, breakage and pattern matching. A straight laminate lay at 10% needs far less than a herringbone layout at 20%.
Can I switch to feet?
Yes. Choose feet in Display units and typed sizes convert, so a 5.5 m room becomes 18.0446 ft. Feet-and-inches shorthand then works. The pack coverage converts from 2 m² to 21.53 sq ft.