Wallpaper calculator with repeat.
Five match types, one wall, every drop priced in paper.
A repeat does not add a fixed percentage; it rounds every drop up to whole patterns, and a drop match makes alternate drops start part way through. This calculator cuts each drop for a straight, half-drop, third-drop, quarter-drop or random match, shows the paper each one loses to the match, and fits the cuts on rolls.
02 / Drops and pattern lines
03 / Rolls
- Drops
- —
- Longest cut
- —
- Cut total
- —
- Lost to the match
- —
- Per drop
- —
- Drops per roll
- —
- Roll tails
- —
- Add-one-repeat rule
- —
- Area method, 10 %
- —
The two rules print what a shortcut would order. The roll count above is from cuts placed on rolls.
Five matches on the same wall
| Match | Rolls | Longest cut | Cut total | Lost to the match | Yards |
|---|
What each drop carries
Drop by drop
| Drop | Pattern offset | Needed | Cut | Lost to the match | Roll |
|---|
Needed is the wall height; the cut adds the trim allowance and rounds to whole repeats after the offset. Select a drop to read the arithmetic in one line.
What a pattern repeat costs, one drop at a time
The example wall is 12 feet wide and 8 feet high, papered from a 20.5-inch bolt 33 feet long with a 21-inch repeat and a 4-inch trim allowance. Eight drops are needed. Each must be at least 100 inches, and with a straight match each is cut to five repeats, 105 inches: 5 inches lost per drop, 40 in all. A bolt of 396 inches yields three such cuts, so the wall takes three bolts and the ledger says so.
Choose a half-drop match and drops 2, 4, 6 and 8 start half a repeat into the pattern. Their 100 inches plus the 10½-inch offset need six repeats: 126 inches, 26 lost. The wall still takes three bolts, because 126 + 126 + 126 fits in one and 126 + 105 + 105 in the next, but 124 inches now go to the match instead of 40. A third drop offsets drops by a third and two thirds in turn: 145 inches lost. A quarter drop: 166. A random match cuts 100 inches flat and loses nothing to the pattern.
Two rules of thumb, tested
The most quoted rule adds one repeat to every drop: 96 + 4 + 21 = 121 inches, three per bolt, three bolts. It happens to agree here, but it charges 21 inches to a drop that only needed 5, and on a 9-foot wall it would say two cuts per bolt where five repeats of 21, 105 inches, still allow three. The area method divides 96 square feet plus 10 percent by the 56.4 square feet on the bolt and orders two, one short.
The estimators executed for this page fall between those rules. One returned four rolls for this wall with the repeat and two without; one rounded the wall height to five repeats and divided by roll area; one echoed the repeat as zero after it was typed. Their rows are in the table below, with the inputs used.
How ranking estimators handle the repeat
| Estimator | Basis observed | Inputs | Outputs |
|---|---|---|---|
| Wallpaper Direct calculator | wall area per wall (whole feet and inches), doors and windows deducted by area, fixed 10 % wastage checkbox, rolls of 52 cm × 10 m | 12 × 8 ft wall, pattern repeat typed as 1 ft 9 in twice | wall area 96.0 ft², pattern repeat echoed 0 ft 0 in, +9.6 ft² wastage, total 105.6 ft², 'You'll need 3 rolls' |
| Thibaut wallpaper calculator | total wall width and ceiling height in decimal feet, roll width in inches, roll length in yards, repeat in inches; recommends not deducting openings and ordering up to 20 % more | 12 ft wide, 8 ft high, roll 20.5 in × 11 yd, repeat 21 in; then repeat 0 | Estimated Rolls Needed 4; with repeat 0: 2 |
| DecoratorsBest estimator (rolls and yards tabs) | wall height plus up to four wall lengths, horizontal and vertical repeat, roll width and length or yards; one roll count after Calculate (execution recorded by the previous session on 2026-09-09) | the test browser was redirected to google.com on 2026-09-10 in headless and headed Chrome | not re-executed; no openings field, no strip plan (2026-09-09 record) |
| Omni Calculator wallpaper | single wall or rectangular room, doors and windows by count and size, roll length and width, pattern repeat, cost per roll; adjusted height and adjusted wall area fields | single wall 3.66 × 2.44 m, roll 10.06 × 0.52 m, repeat 0.533 m | wall surface area 8.93 m²; adjusted height 2.665 m, which is five whole repeats of 0.533 m (the height rounded up to the repeat, no trim allowance); rolls then follow from adjusted area ÷ roll area |
| Romo wallcovering calculator | roll width and length, repeat type straight / half drop / random, vertical repeat, 10 % wastage checkbox, walls in feet and inches | page read; result text not captured after submit | the only ranking tool with a match-type selector |
| Phillip Jeffries yardage calculator | perimeter × height ÷ roll width, rounded up to whole linear yards | registered as 100 sq ft; width 36 then 54 in | 12 linear yards at 36 in, 8 at 54 in |
| Carnegie wallcovering calculator | square footage or length × height ÷ product width (36 to 118 in) → linear yards | 54 in, 40 × 10 ft | 30 linear yards |
| Mahones, Cole & Son, Jane Clayton, Innovations | wall dimensions and roll dimensions → rolls (Mahones single and double rolls; Cole & Son roll dimensions from product pages; Jane Clayton UK with repeat and trim allowance; Innovations material width → yards) | forms read; outputs not captured in the test browser | none recorded |
Horizontal repeat and what it does not change
Labels also state a horizontal repeat, the width of the pattern across the roll. It decides where the pattern lands at the seams and which way a corner is trimmed, not how much paper a drop needs; the drop count comes from the roll width alone. The vertical repeat is the number this page consumes. When the label gives an offset match in inches rather than a fraction, enter that vertical repeat and choose the drop that matches the offset described.
Doors, windows and four walls sharing rolls are handled on the general wallpaper calculator, with the same drop engine and the same rounding. This page keeps one wall so the match can be read cleanly.
Questions about the repeat
How do you calculate wallpaper with a repeat pattern?
Cut each drop to the wall height plus a trim allowance, then round that up to whole repeats so the pattern lands the same way on every drop. For a straight match every drop rounds the same way; for a drop match, alternate drops start part way into the repeat and may round to one more. Count how many such cuts a roll holds.
What is the formula?
Drops equal wall width divided by roll width, rounded up. Cut length equals the ceiling of (height + trim + offset) ÷ repeat, times the repeat, where the offset is zero for a straight match and a fraction of the repeat for a drop match. Rolls come from fitting those cuts on rolls, not from dividing area.
How many rolls of wallpaper will I need?
For the example wall, 12 by 8 feet on a 20.5-inch bolt with a 21-inch repeat, eight drops cut to 105 inches take three 33-foot bolts, three drops per bolt. The same wall with a half-drop match still takes three bolts, but 124 inches of paper instead of 40 go to the match. The table above runs all five matches at once.
What would 200 square feet cost?
This page prices nothing; it returns drops, cuts and rolls for the roll you enter. Multiply the roll count by the price on the label. Two hundred square feet of wall is not two hundred square feet of paper, because the drops carry the trim and the repeat rounding shown in the bars.
Can I enter the repeat in inches with fractions?
Yes. Every length field reads feet, inches and fractions, so a 20 1/2-inch roll and a 25 1/4-inch repeat are typed as written. Cuts are reported in feet and inches to the sixteenth, and the CSV keeps millimetres.
What about windows and doors?
This page isolates the repeat on one plain wall. The general wallpaper calculator places doors and windows on the wall and shortens only the drops they span, with the same repeat rules; use it when an opening is in play and read the per-drop cuts here to understand what changed.
Is this a one-wall calculator?
Yes, deliberately. The repeat is a per-drop question, and one wall shows it cleanly: which drops start part way into the pattern, which round up to an extra repeat, and how many of those cuts a roll holds. Four walls sharing rolls are handled on the general page.
Is this repeat calculator free?
Yes, with no email step. The comparison table, the per-drop table, the bar chart and the CSV of all five matches are available as they are. The preloaded roll, repeat and trim are examples to overwrite with the label values.
Do other free calculators handle the repeat?
The ones executed for this page take one repeat number and return one roll count. One returned four rolls for the example wall with the repeat and two without; one rounded the wall height to whole repeats; one echoed the repeat as zero after it was typed. None showed a cut per drop or offered a drop match.
Why do results differ from an inches-only tool?
Rounding. A tool that adds one repeat to the height treats a 96-inch wall and a 21-inch repeat as 117 inches per drop; this page rounds 100 inches, height plus trim, up to 105, the nearest whole number of repeats. Over eight drops that is 96 inches of paper, and on a 33-foot bolt it can be the difference between three cuts per roll and two.
Which tool should I use for the whole room?
Start here to choose the match and see its cost, then move to the general wallpaper calculator for the four walls, the openings and the roll sheet. Both use the same drop engine, so the cut lengths agree.
What makes a repeat calculator good?
It should show the offset of each drop, the cut it rounds to, and the waste that rounding creates, for the match type on the label rather than a single generic repeat. It should also print the rules of thumb next to the plan so the difference can be seen instead of assumed.
What the match table does not decide
- One wall, no openings; the general calculator handles those. Drop matches are modeled as an offset of the repeat divided by the step count on successive drops.
- The first drop is assumed to start at a repeat boundary; a hanger may shift the pattern to place a motif at the ceiling, which can add up to one repeat to every drop.
- Trim allowance is one value per drop. Out-of-level ceilings or baseboards may need more.
- Rolls are filled longest cut first; a different cutting order can change which roll a drop comes from but not the count in the examples shown.
- No prices, adhesive or booking times. Estimator outputs in the table are quotes of what those tools returned on the day.