Wallpaper Roll Calculator — Pattern Repeat & Physical Bolt Planner
Plan full-height strips rather than relying on wall area alone. See how repeat, trimming and the actual continuous roll length change your order.
Example inputs only — replace them with your own measurements and prices.
Your result
Enter your details and calculate. Results and assumptions appear here.
How this calculation works
Strips = ceiling(wall width ÷ roll width). Free-match cut length = wall height + combined trim. Straight-match cut length rounds that length up to a whole repeat. Drop-match planning length adds one full repeat. Matched patterns reserve another full repeat per roll for initial alignment. Strips per roll = floor((roll length − alignment reserve) ÷ cut length). Rolls = ceiling(strips ÷ strips per roll) + chosen spares.
Assumptions and limitations
A deliberately conservative plan for one rectangular wall. Do not deduct doors or windows; offcuts may not fit elsewhere. It is not a precise A/B drop cutting optimisation and can overestimate. Check unusually large repeats, half/third drops and custom murals with your decorator. US rolls may be priced as single rolls but supplied as double-roll bolts: use physical length and matching price. Check dye lots before ordering.
Sources and verification
- Graham & Brown: measuring walls
- Graham & Brown: match types and repeat
- Graham & Brown: measuring walls
See the manufacturer references above before ordering. WebToolzHub is not affiliated with these organisations.
How many wallpaper rolls do I need?
Enter the wall width and height, then copy the width, continuous length and pattern repeat from the wallpaper label. Choose the match type before calculating. The result shows full-height strips, the planned length of each cut, strips available from one physical roll and a purchase quantity including your chosen spare rolls.
Worked example: a 4 m feature wall
For a wall 400 cm wide and 240 cm high, a 53 cm-wide roll requires 8 strips: 400 ÷ 53 rounds up. With 10 cm combined trimming and a 32 cm straight repeat, each planned cut is 256 cm. This tool reserves 32 cm from a 1,005 cm roll for initial alignment, leaving room for 3 full strips. Eight strips therefore need 3 physical rolls, or 4 when you choose one spare. At 35 per physical roll, the displayed purchase cost is 140 in your chosen currency.
UK rolls and US double-roll bolts
Use centimetres for the metric option or inches for every dimension in the US option. Convert feet to inches by multiplying by 12 before entering them. Product lengths vary: the sample is an example, not a standard that fits every product. If a US supplier quotes a single-roll price but sells a continuous double-roll bolt, enter the bolt's full length and full price together. Mixing a half-bolt price with a full-bolt length understates the cost.
Why wall area alone can undercount
An area estimate does not tell you whether another full-height strip fits in the remaining paper. Pattern matching, trimming and roll-end offcuts reduce the usable yield. This calculator therefore works with strips. Its drop-match option is a conservative purchasing allowance, not a cutting sequence for alternating A/B strips.
Frequently asked questions
Should I subtract doors and windows?
This tool does not deduct them. That keeps the estimate conservative because an offcut from an opening may not fit another position or match its pattern. For large openings or expensive paper, ask your installer for a measured cutting plan.
Can I calculate a whole room?
Calculate each wall separately and keep a note of the required strips. Adding separately rounded roll quantities may overestimate because usable offcuts can sometimes be shared. Do not add a spare roll to every wall unless that is your intention.
Does changing units convert my current measurements?
No. Changing units loads example measurements for that unit system and clears the previous result. Enter your own values again before calculating.
Can I save the estimate?
Use Download CSV for a spreadsheet summary, or Copy summary to paste the result into your project notes. The file includes calculation assumptions so the quantity can be reviewed before ordering.
The calculator itself runs in your browser without sending inputs to an API or saving them. The hosting website may have its own cookies or analytics. JavaScript is required for interactive results.