The source recommends allowing an additional repeat so there is more choice over where the design sits on the wall.
Wallpaper Measuring Guide
How to Measure for Wide-Width Wallpaper
Wide-width wallpaper is often sold by the metre rather than as a standard roll, so the quantity calculation is different. This guide shows how to work out the number of drops, repeat allowance, drop length and final meterage for a wall or room.
The worked example comes from the original TM Interiors guide and uses Lewis & Wood Jasper Peony: 135 cm wide, sold by the metre, with a 104.5 cm vertical pattern repeat.
The Worked Example
The source guide uses one wide-width wallcovering to demonstrate the calculation. The same basic sequence can be applied to other widths, but the actual pattern repeat, match type, selling unit and manufacturer instructions must come from the product you are ordering.
Wallpaper width
135 cm
Vertical repeat
104.5 cm
Example wall
450 cm wide × 248 cm high
Standard-roll calculations are different. If you are working with a conventional roll rather than a by-the-metre wide-width product, see our Estimating Wallpaper Quantities guide instead.
1. Calculate How Many Drops You Need
Measure the width of the wall and divide it by the usable width of the wallpaper. If the answer is not a whole number, round up because a partial final drop still requires another full width of wallcovering.
Formula
Wall width ÷ wallpaper width = number of drops
Source example
450 cm ÷ 135 cm = 3.34
Round 3.34 up to 4 drops.
4
drops are required to cover the example 450 cm wall.
2. Calculate the Number of Pattern Repeats per Drop
Where the wallcovering has a vertical pattern repeat, the source method next divides the wall height by that repeat.
Formula
Wall height ÷ vertical pattern repeat = repeats needed per drop
Source example
248 cm ÷ 104.5 cm = approximately 2.38 repeats
The original guide then treats the example as a half-drop repeat and rounds the required amount to 2.5 repeats.
Pattern match matters. The original guide distinguishes between straight and half-drop repeats. For a straight match it rounds up to the next whole repeat. For its half-drop example it uses the next half-repeat increment. Apply this only where it matches the repeat and cutting logic supplied for the wallcovering you are using.
3. Calculate the Final Drop Length
Once the source example has established how many repeats are needed, it multiplies that figure by the vertical pattern repeat.
Formula
Number of repeats × vertical repeat = calculated drop length
Source example
2.5 × 104.5 cm = 261.25 cm
The original guide rounds this example up to a working drop length of 262 cm.
262 cm
final example drop length used for the remaining calculations.
The actual cut length for another wallcovering may also be influenced by motif positioning, trimming allowance and the manufacturer’s pattern-match instructions.
4. Calculate the Final Meterage for One Wall
Multiply the number of drops required by the final drop length.
Formula
Number of drops × final drop length = total wallcovering length
Source example
4 drops × 262 cm = 1,048 cm
1,048 cm = 10.48 metres.
10.48 m
calculated meterage for the example 450 cm wide wall.
5. Estimate Wide-Width Wallpaper for a Whole Room
The source then treats the room as a continuous perimeter — effectively “flat-packing” the walls — and ignores ordinary doors and windows for this worked estimate unless an opening is unusually large.
Source room example
Two walls at 4.5 m and two walls at 3.47 m:
(4.5 × 2) + (3.47 × 2) = 15.94 m perimeter
15.94 m ÷ 1.35 m wallpaper width = 11.81
Round up to 12 drops.
12 drops × 2.62 m = 31.44 metres.
31.44 m
calculated meterage for all four walls in the source example, before any extra ordering allowance.
| Stage | Worked figure | Result |
|---|---|---|
| Room perimeter | (4.5 × 2) + (3.47 × 2) | 15.94 m |
| Required drops | 15.94 ÷ 1.35 | 11.81 → 12 drops |
| Drop length | 2.5 × 104.5 cm | 261.25 cm → 262 cm |
| Calculated room meterage | 12 × 2.62 m | 31.44 m |
6. Extra Ordering & Cutting Tips from the Original Guide
The source recommends an additional drop, or two on a larger project, as an allowance for accidents and errors.
Where the source calculation rounds to a half repeat such as 2.5 or 3.5, it recommends cutting the room drops in sequence: 1, 2, 3, 4 and so on.
Where the source calculation rounds to a whole repeat such as 3, 4 or 5, it suggests an alternating cutting order — 1, 3, 5, 7 followed by 2, 4, 6, 8 — to economise on a half-drop design.
Before ordering: check the actual wallpaper width, selling unit, repeat, match type and hanging instructions. The figures above reproduce the logic of the original TM Interiors worked example; they are not a fixed quantity allowance for every wide-width wallcovering.
Wide-Width Wallpaper Measuring FAQs
How do I calculate how many wide-width wallpaper drops I need?
Divide the wall width by the width of the wallcovering and round up to the next whole drop. In the source example, 450 cm ÷ 135 cm = 3.34, so four drops are required.
Does the pattern repeat affect how much wallpaper I need?
Yes. The original guide calculates a drop length from the wall height, vertical pattern repeat and match type before multiplying that drop length by the number of required drops.
Can I use a standard wallpaper roll calculator for wide-width wallpaper?
Not always. The source guide is specifically for wider products that may be sold by the metre. Standard 52 cm rolls are covered separately in our Wallpaper Quantity Guide.
Should I deduct doors and windows?
In its whole-room example, the source ignores ordinary doors and windows unless an opening is especially large. This provides a working estimate and retains material for pattern matching and cutting.
Should I order exactly the calculated meterage?
The original guide recommends additional material for motif placement and possible cutting errors rather than ordering only the bare calculated figure.
Related Wallpaper Guides
Wide-width wallpaper is calculated drop by drop
Start with the actual product width and repeat, work out the required drop length, then multiply by the number of drops — and allow sensible extra material before ordering.
