Pattern repeat calculator
Matching a patterned fabric means every piece has to start at the same point in the design, so each cut length is rounded up to a whole number of pattern repeats: a 255 cm cut in a fabric with a 64 cm repeat becomes 256 cm, and the surplus is trimmed away. The calculator below works out the matched cut length, the fabric lost from every piece, one extra repeat for placing the first cut, and the total — alongside what the same pieces would take in a plain fabric, which is the true cost of the pattern.
Your pieces and the repeat
10.9 m
12 yd · the pieces need 10.88 m
- Cut length for each piece
- 256 cm4 whole repeats, from 255 cm needed
- Trimmed off every cut
- 1 cm4 cm across every piece together
- What the matching costs
- 68 cmthe same pieces in a plain fabric would take 10.2 m
- Fabric that ends up in the pieces
- 99.6%of every cut, before the placement allowance
- Placement allowance
- 64 cmone repeat, so the first cut starts where you want
If the motif steps down by half a repeat between adjacent widths rather than matching straight across, add half a repeat for every width after the first. This calculator assumes a straight repeat.
How we got this
- Cut length before matching — 255 cm220 cm finished + 35 cm allowances
- Repeats each cut has to span — 4 repeats⌈255 cm ÷ 64 cm⌉
- Cut length matched to the repeat — 256 cm4 × 64 cm
- Trimmed off every cut — 1 cm256 cm − 255 cm
- Fabric for the cuts — 1024 cm4 × 256 cm
- Pattern placement allowance — 64 cmone extra repeat, so the first cut can start where you want in the design
- Total fabric required — 1088 cmcuts + placement allowance
- Buy, rounded up (nearest 10 cm) — 1090 cm1088 cm rounded up to the next 0.1 m
What matching a pattern actually requires
A printed or woven design repeats up the roll at a fixed interval. If two pieces of that fabric are going to hang side by side — two halves of a pair, two blinds in the same window, two lengths joined into one curtain — the design has to sit at the same height in both, or the eye reads the mismatch instantly.
Getting that alignment costs nothing at the sewing machine and everything at the roll. The rule is simply that every piece must be cut to a whole number of repeats. A cut that needs 255 cm in a fabric repeating every 64 cm cannot be 255 cm; it is 256 cm, four whole repeats, and the extra centimetre is trimmed away. The next piece then starts at the same point in the design as the one before it, and so does every piece after that.
The rounding is always upward, never to the nearest. Rounding down would produce a piece too short to make, which is not a saving but a wasted cut — and unlike buying slightly too much, it cannot be undone once the cloth has been cut.
A worked example
Four pieces, each finishing at 220 cm with 35 cm of heading and hem allowances, in a fabric with a 64 cm repeat. The table is generated by the calculation, not typed out.
| Step | Working | Result |
|---|---|---|
| Cut length before matching | 220 cm finished + 35 cm allowances | 255 cm |
| Repeats each cut has to span | ⌈255 cm ÷ 64 cm⌉ | 4 repeats |
| Cut length matched to the repeat | 4 × 64 cm | 256 cm |
| Trimmed off every cut | 256 cm − 255 cm | 1 cm |
| Fabric for the cuts | 4 × 256 cm | 1024 cm |
| Pattern placement allowance | one extra repeat, so the first cut can start where you want in the design | 64 cm |
| Total fabric required | cuts + placement allowance | 1088 cm |
| Buy, rounded up (nearest 10 cm) | 1088 cm rounded up to the next 0.1 m | 1090 cm |
Each piece needs 255 cm of cloth, which falls 1 cm short of 4 whole repeats — so the cut length becomes 256 cm and that 1 cm comes off every piece. Four cuts plus one repeat for placement gives 10.88 m, against 10.2 m for the same four pieces in a plain fabric. The design is costing 68 cm, most of it the placement allowance rather than the matching itself.
Why an inch either way changes the price
The waste per piece is not proportional to anything. It depends entirely on where your cut length happens to fall between two repeats, which makes small changes in the finished length disproportionately expensive — or free. Every row below is the same four pieces in the same 64 cm fabric, differing only in the finished length.
| Finished length | Cut needs | Matched cut | Trimmed per piece | Total to buy |
|---|---|---|---|---|
| 190 cm | 225 cm | 256 cm | 31 cm | 10.9 m |
| 200 cm | 235 cm | 256 cm | 21 cm | 10.9 m |
| 210 cm | 245 cm | 256 cm | 11 cm | 10.9 m |
| 220 cm | 255 cm | 256 cm | 1 cm | 10.9 m |
| 230 cm | 265 cm | 320 cm | 55 cm | 13.5 m |
| 240 cm | 275 cm | 320 cm | 45 cm | 13.5 m |
A 190 cm finished length and a 240 cm finished length are 50 cm apart at the window and can sit in the same repeat band, buying identical amounts of fabric. Cross a boundary and the total jumps by a whole repeat on every piece at once. This is the single most useful thing to know before ordering a patterned fabric: check where you are in the band, because a centimetre of hem depth may be worth several metres of cloth.
Three ways to pay less for a pattern
Absorb the surplus into the hem. If each piece is trimming 40 cm to reach the next repeat, that 40 cm can go into a deeper hem instead of the offcuts. It costs nothing, the fabric is already bought, and a deeper hem hangs better on a long curtain. Nothing about the finished appearance changes except for the better.
Move the finished length, if the room allows. Where a cut clears its last repeat by only a few centimetres, losing those centimetres drops a whole repeat from every piece. The calculator flags this case explicitly, with the amount and the saving, because it is invisible in a total that only shows the answer.
Decide about the placement allowance deliberately. The extra repeat exists so you can choose where in the design the first cut begins — a complete motif at the hem rather than one sliced in half. On a large repeat it is the biggest single line in the total. It is worth having on a statement fabric and worth skipping on a small all-over print where nobody will ever locate the motif.
Reading a fabric label
Four things a label may call a repeat, only one of which this calculator models. See also pattern repeat and half-drop repeat in the glossary.
- Vertical or straight repeat. The distance up the roll before the design starts again. This is the number this calculator wants, and the number that governs cut length.
- Horizontal repeat. The distance across the roll. It matters when widths are joined side by side, because the design must also line up across the seam, but it does not change how long each cut has to be.
- Half-drop repeat. The design steps down by half a repeat between adjacent widths instead of matching straight across. Each width after the first then needs an extra half repeat, which this calculator does not add — it warns instead.
- Random or free match. Textures, plains and some stripes have no vertical repeat to respect. Enter zero and the cut is simply the finished length plus its allowances.
How to measure for this
- Find the repeat on the label. Furnishing fabrics list a vertical repeat, sometimes called the straight or pattern repeat, in centimetres or inches on the bolt end or the online listing.
- Or measure it yourself. Pick a distinctive point on a motif and measure up the roll to the identical point on the next one. That distance is the repeat, whatever the size of the motif itself.
- Add up the allowances on one piece. Heading turn-down, hem and any turnings, added together. A double 10 cm hem consumes 20 cm of cloth, not 10.
- Count the pieces, not the curtains. Each fabric width cut from the roll is one piece. A pair of curtains made from two widths each is four pieces.
- Read the matched cut length and the total. The cut length is the figure to give the shop or to mark on the roll. The comparison with plain fabric is what the pattern is costing you.
What this assumes
This tool answers one question — what a repeat does to a cut length — and answers it for any project made of equal-length pieces: curtains, Roman blinds, panels, a run of café curtains. It is deliberately not a curtain calculator. It does not know your track width and cannot tell you how many pieces to cut, which is what the curtain fullness calculator is for, and the curtain fabric calculator puts both halves together into a single quantity to buy.
- Every piece is the same length. Pieces of differing lengths can often be nested cleverly against the repeat, and no general formula covers that; work the long pieces first.
- The repeat is exact. Printed fabric can drift by a centimetre or two over several metres, and a woven design can bow across the width. On a long drop, check the roll rather than trusting the label alone.
- The placement allowance is one repeat. That is enough to position the first cut anywhere in the design. It is not enough to also centre a large motif across the width of a made-up curtain.
- The rounding is upward at every step, including the final rounding to whatever length your shop will cut. Buying a little too much is recoverable; a piece cut short is not.
Common questions
- What is a vertical pattern repeat?
- The distance up the roll before the design starts again, printed on the fabric label as the vertical or straight repeat. Measure from one point on a motif to the identical point on the motif above it — that distance, not the size of the motif, is what governs the cut length.
- Why is every cut rounded up to a whole repeat?
- So that all the pieces begin at the same point in the design. Cut them to the exact length instead and each one starts wherever the previous cut happened to end, which puts the motifs at a different height in every piece — obvious at a glance across a pair of curtains or a run of blinds.
- Why add one extra repeat on top?
- Because the roll is cut wherever the roll happens to be. Without a placement allowance you have to start the first piece at whatever point in the design the shop cut, which may put a motif half-way off the hem. One spare repeat buys the freedom to start where you choose.
- Is a large repeat always more expensive?
- It is more wasteful per piece, but what matters is where your cut length falls against the repeat. A 200 cm cut in a 50 cm repeat wastes nothing, while a 205 cm cut in the same fabric wastes 45 cm on every piece. Lengthening a hem to absorb that surplus is usually free.
- What about a half-drop repeat?
- A half-drop steps the design down by half a repeat between adjacent widths, so each width after the first needs an extra half repeat to bring it back into line. This calculator assumes a straight repeat, which is what most furnishing fabrics use, and warns you when the difference applies.
Related tools
Curtain fabric calculator
Track width, drop, fullness and pattern repeat in; metres or yards to buy out, with every allowance adjustable.
Roman blind fabric calculator
Fabric and lining for a flat blind — no fullness, but the repeat still decides the cut.
Curtain fullness calculator
How many widths each curtain needs at the fullness you want — and what whole widths really gather to.
Fabric width converter
Pattern written for one bolt width, fabric bought at another — work out the equivalent length.