Wallpaper Calculator: Stop Guessing and Order the Right Number of Rolls First Time
Here's a situation nobody enjoys: you're two walls in, the paste is mixed, and you've just realised you're a roll short. Or worse, you've got six spare rolls gathering dust in the garage because someone eyeballed it. Either way, it costs you — time, money, or both. This guide walks you through measuring your walls, running the numbers, and ordering with confidence — whether you're tackling a small bathroom, a bold feature wall, or a full room.
How to Calculate How Much Wallpaper You Need
Getting the right amount of wallpaper is a bit like packing for a holiday: underdo it and you're in trouble, overdo it and you're lugging dead weight. Here's a step-by-step take-off that gets it right.
Step 1: Measure Your Walls
Grab a tape measure and note the height and width of every wall you're covering. Write them down in metres (m) or feet (ft) — whichever you think in.
- For all four walls: Add the widths of each wall together, then multiply by the height.
- For a feature wall: Only measure the width and height of the wall you want to cover.
Tip: Subtract the area of large windows and doors if you want to be precise — it all adds up.
Step 2: Calculate Total Wall Area
Multiply your total width by the height to get the total area in square metres or square feet. Simple as that.
- Example:
- Width: 10m (32.8ft)
- Height: 2.4m (7.87ft)
- Total area: 10m x 2.4m = 24m² (32.8ft x 7.87ft ≈ 258ft²)
Step 3: Check the Wallpaper Roll Coverage
Wallpaper rolls vary, but a standard UK roll typically covers about 5.2m² (56ft²). Think of the label as the spec sheet — always check it before you commit.
| Roll Size | Metric Coverage (approx) | Imperial Coverage (approx) |
|---|---|---|
| Standard UK Roll | 0.52m x 10m | 21in x 33ft |
| Coverage | 5.2m² | 56ft² |
Step 4: Divide Wall Area by Roll Coverage
Divide your total wall area by the coverage of one roll. That's your roll count — before rounding.
Formula:
Number of rolls = Total wall area ÷ Roll coverage
- Example continued:
- Wall area: 24m²
- Roll covers: 5.2m²
- 24 ÷ 5.2 = 4.62 rolls
- Always round up, so you'll need 5 rolls.
Step 5: Account for Pattern Repeat and Wastage
Pattern repeat is the bit that catches people out. If your wallpaper has a design that needs to line up between drops, you'll lose material matching it — like trying to wrap a gift in striped paper and getting the stripes to run straight. Check the pattern repeat on the roll's label and add 10–15% extra, especially for large or bold patterns.
For plain or small-repeat designs, 10% extra is usually sufficient — think of it as the spare teabags you keep so you're never caught short.
Step 6: Use a Wallpaper Calculator for Fast Results
If you'd rather skip the maths entirely, our wallpaper calculator does the heavy lifting for you. Plug in your measurements and it spits out a roll count in seconds.
Worked Example (Metric and Imperial)
You want to wallpaper a room that is 12ft by 12ft (3.66m x 3.66m) with a standard 8ft ceiling (2.44m).
- Step 1: Find total wall width. Four walls, each 12ft wide = 48ft (or 4 x 3.66m = 14.64m)
- Step 2: Multiply by height. 48ft x 8ft = 384ft² (14.64m x 2.44m = 35.73m²)
- Step 3: Standard roll covers 56ft² (5.2m²)
- Step 4: 384 ÷ 56 = 6.86 rolls (35.73 ÷ 5.2 = 6.87 rolls)
- Step 5: Round up and allow for pattern repeat. Buy 8 rolls to be safe.
Tips for Different Room Types
Not every room is a neat rectangle — and some jobs have quirks worth knowing about before you start ordering.
- Small bathrooms: Subtract windows and doors. Add extra if the walls are uneven.
- Feature walls: Only measure the wall you want to cover — no need to price the whole room.
- Rooms with unusual shapes: Break your measurements into sections and add them up. Treat it like a jigsaw: work out each piece separately, then total them.
How Much Wallpaper Paste or Adhesive Do You Need?
Most wallpaper pastes state the coverage per pack on the label. As a rule, one standard packet covers 5–7 rolls — but always check the instructions for your chosen brand and wallpaper type. Some heavier papers drink paste like it's going out of fashion.
Questions People Are Actually Asking
How much wallpaper do I need?
Measure the total wall area (width x height), subtract windows and doors, then divide by the coverage per roll. Always round up to the nearest whole roll and chuck in a bit extra for pattern matching — you'll thank yourself later.
How much wallpaper for a small bathroom?
Measure each wall's width and height, subtract the area of windows and large fixtures, then run through the main calculation steps. Bathrooms often need 2–4 rolls, but your own measurements are the only ones that matter.
How much wallpaper paste do I need?
One standard packet of wallpaper paste usually covers 5–7 rolls. Check your wallpaper's label and the paste brand's guidance, as some heavy wallpapers may require more paste.
How much wallpaper adhesive do I need?
Adhesive requirements are similar to paste. For most rooms, one large tub or two small packets will suffice for a typical project of 5–8 rolls. Always check product instructions for coverage specifics.
How much wallpaper for one wall?
Measure the width and height of that wall, multiply to get the area, then divide by the coverage per roll. Most standard feature walls need 1–2 rolls, depending on size and pattern.
How much wallpaper for a 10x10 room?
A 10ft x 10ft room with an 8ft ceiling has a total wall area of 320ft² (29.6m²). With standard rolls covering 56ft² (5.2m²), you'll need 6–7 rolls, plus a bit more for pattern matching.
How much wallpaper is in a roll?
A typical UK roll measures 0.52m x 10m (21in x 33ft), covering around 5.2m² (56ft²). Always check the packaging for exact measurements — don't assume.
How much wallpaper for a 12x12 room?
A 12ft x 12ft room with an 8ft ceiling has a total wall area of 384ft² (35.7m²). This usually requires 7–8 rolls, allowing for pattern repeat and wastage.
Conclusion
Ordering without a proper take-off is like doing the weekly shop with no list and a blindfold — you'll either come home short or spend a fortune on stuff you don't need. A tape measure, five minutes, and the right formula is all it takes. Ready to get it done? Use our wallpaper calculator to check your measurements and order with confidence.
Free Tools to Put This into Practice
Reading is one thing — working out your own numbers is what saves time and money. Here are the free HowMuchDoINeed calculators that pair best with this guide:
- Wallpaper Calculator — work out exactly how much you need and what it will cost.
- Paint Calculator — work out exactly how much you need and what it will cost.
- Retaining Wall Calculator — work out exactly how much you need and what it will cost.
Explore every free calculator on HowMuchDoINeed — no sign-up required.