Cushion fabric calculator
A cushion cover is a front, a back in one piece or two, and often a run of piping — so the fabric it takes depends on how those rectangles pack across your roll rather than on their total area. An envelope back adds two pieces of about 60% of the cover height each, a zip adds one the size of the front, and piping is cut in strips across the width. The calculator below builds that piece list from your cover size, packs it onto the roll and prints the cutting plan, in metric or imperial.
Your cushions
Borders, seams and the roll
2 m
2¼ yd · the cutting plan needs 1.92 m
- Pieces to cut
- 124 × front, 8 × envelope back
- Cover size
- 45 cm × 45 cmfinished, before seam allowances
- Rows in the cutting plan
- 41.92 m of cloth
- Cloth that ends up in the covers
- 81%of the area you pay for
The cutting plan, row by row
| Row | Pieces across | Width used | Row length |
|---|---|---|---|
| 1 | 2 × frontEnvelope back (turned) | 131 cm9 cm spare | 48 cm |
| 2 | 2 × frontEnvelope back (turned) | 131 cm9 cm spare | 48 cm |
| 3 | 2 × envelope backEnvelope back (turned) | 131 cm9 cm spare | 48 cm |
| 4 | 2 × envelope backEnvelope back (turned) | 131 cm9 cm spare | 48 cm |
A cover cut to the same size as its pad hangs slack at the corners and looks half empty. Make the cover 2–3 cm smaller in each direction than the insert and the filling pushes it out to a full, square shape.
How we got this
- Envelope back pieces — 45 cm × 32 cm2 per cushion, each 60% of 45 cm + 5 cm hem
- Pieces to cut — 12 pieces4 × front, 8 × envelope back, each grown by 3 cm for seams
- Rows in the cutting plan — 4 rowspieces laid across 140 cm of usable width, widest first, some pieces turned sideways
- Fabric for the rows — 192 cm48 cm + 48 cm + 48 cm + 48 cm
- Total fabric required — 192 cmrows
- Buy, rounded up (nearest 10 cm) — 200 cm192 cm rounded up to the next 0.1 m
Cut the cover smaller than the pad
This is the one piece of advice that changes how a finished cushion looks, and it is the opposite of what feels right: a cover for a 45 cm insert should be made at about 42–43 cm.
A cover cut to the same size as its pad has nothing pushing it out. The corners droop, the seams show a little slack, and the whole thing reads as tired even when it is new. Undersize it by two or three centimetres and the filling has to expand into the cover, which pulls the seams straight and squares the corners off. Feather inserts take the larger difference happily; foam and hollowfibre are firmer, so stay nearer two.
The calculator asks for the finished cover and adds seam allowances to it, so enter the reduced figure rather than the insert size.
The back is where the fabric goes
A front is one rectangle. A back is either one rectangle or two, and the choice is worth understanding because it is not the obvious one.
An envelope back is two pieces that overlap across the opening. Each is about 60% of the cover height plus 5 cm for the hems on the opening edges, so together they come to roughly 120% of the cover — more cloth than a single back. No zip, no zip foot, and nothing to break.
A zipped back is one piece the size of the front, with the zip set into a seam. Less cloth on paper, but the two shorter envelope pieces often drop into a row where a full-height back would not fit, so on a given roll width the envelope can come out level or even cheaper. The calculator prices both and tells you which way your particular job falls.
A worked example
Four covers finishing at 45 × 45 cm, envelope backs, no piping, from a 140 cm plain fabric with 1.5 cm seams. The table below is generated by the calculation, not written out.
| Step | Working | Result |
|---|---|---|
| Envelope back pieces | 2 per cushion, each 60% of 45 cm + 5 cm hem | 45 cm × 32 cm |
| Pieces to cut | 4 × front, 8 × envelope back, each grown by 3 cm for seams | 12 pieces |
| Rows in the cutting plan | pieces laid across 140 cm of usable width, widest first, some pieces turned sideways | 4 rows |
| Fabric for the rows | 48 cm + 48 cm + 48 cm + 48 cm | 192 cm |
| Total fabric required | rows | 192 cm |
| Buy, rounded up (nearest 10 cm) | 192 cm rounded up to the next 0.1 m | 200 cm |
Twelve pieces in all — four fronts and eight back pieces — packing into 4 rows for 1.92 m, bought as 2 m. 81% of the cloth ends up in the covers, which is high for a small job: at this size two pieces sit side by side across the roll with little left beside them.
What piping adds
Piping is cut in strips that run across the roll, each one yielding a roll-width of finished piping and costing 4 cm of length. Because the strips are full width, they add up in a way that surprises people on a small job — and running short of piping halfway round the fourth cushion is a genuinely annoying way to be sent back to the shop.
| Cover size | Plain | With piping | Piping needed | Strips |
|---|---|---|---|---|
| 40 cm | 1.5 m | 1.7 m | 6.8 m | 5 |
| 45 cm | 2 m | 2.2 m | 7.6 m | 6 |
| 50 cm | 2.6 m | 2.9 m | 8.4 m | 6 |
| 55 cm | 2.8 m | 3.1 m | 9.2 m | 7 |
| 60 cm | 3.1 m | 3.4 m | 10 m | 8 |
Note how the plain column climbs in steps rather than smoothly: 40 cm and 45 cm covers pack the same way, and the jump comes when a cover grows past the point where two still sit side by side. That is the whole reason this site prints a cutting plan rather than an area — a centimetre on the cover size can be free or can cost a row.
Straight grain or bias?
Straight-grain strips are cut parallel to the selvedge or across it, and they work on anything with straight edges. They lie flat along a side and turn a square corner with a small snip into the seam allowance.
Bias strips are cut at 45°, which lets the piping curve smoothly — round cushions, bolster ends, scalloped edges, any corner with a real radius. The cost is about 41% more cloth, because a diagonal strip covers less of the roll for the same run of piping, and more joins, because bias strips come off shorter. The calculator applies that factor and shows both strip counts.
How to measure and choose
- Measure the insert, not the old cover. An old cover has stretched. Measure the pad itself across its middle, from seam to seam, in both directions.
- Take 2–3 cm off each way. That is the finished cover size. A cover slightly smaller than its insert is what makes a cushion look plump rather than tired.
- Choose the back opening. An envelope back is two overlapping pieces and needs no notions. A zip is one piece the size of the front, plus the zip itself.
- Decide about piping. Piping is cut from the same fabric in strips across the roll, so it adds to the quantity. Straight grain for square cushions, bias for curves.
- Read the plan, not just the number. The cutting plan shows which pieces share a row. If a row is half empty, a slightly different cover size or one more cushion will use it.
What this assumes
- Square or rectangular covers. A round cushion is cut from the square that encloses it, so enter the diameter for both dimensions and expect real offcuts. A boxed cushion with a gusset is closer to the upholstery calculator, which models gussets as pieces.
- Front and back from the same fabric. Backing four cushions in a plain cotton is a common economy and halves the face fabric — run the calculator twice, once per fabric, if you are doing that.
- The cover face has no seam. A cover wider than the roll is refused rather than seamed across the front, because a join down the face of a cushion is a defect, not a solution.
- Zips, cord, pads and thread are not fabric and are not counted. The piping figure is the fabric that covers the cord, not the cord itself.
Cutting several different things from one length? The fabric yardage calculator handles identical rectangles of any size, and the pattern repeat calculator works out what matching a design costs on its own.
Common questions
- What size should the cover be for my insert?
- Make the cover 2–3 cm smaller in each direction than the insert. A cover cut to the same size as its pad hangs slack at the corners; one cut slightly under is filled out by the insert and holds a square, plump shape.
- Does an envelope back use more fabric than a zip?
- Usually a little more cloth in total — two pieces of roughly 60% of the cover height each, against one piece the size of the front — but not always more length, because the two shorter pieces often pack into a row a full-size back would not fit. The calculator costs both and tells you which wins on your roll.
- How much fabric does piping need?
- A 45 cm cushion needs about 1.9 m of piping, and strips are cut across the roll, so each strip yields one roll-width of piping and costs 4 cm of length. Four cushions therefore take six or seven strips — around 25 cm of fabric, which is why piping is the thing people most often run short of.
- Should piping strips be cut on the bias?
- On a square cushion the straight grain is fine and costs less. Bias strips are for curves — round cushions, bolster ends, piped corners with a tight radius — and take about 41% more fabric because a diagonal strip covers less of the roll for the same length.
- What about a patterned fabric?
- Each row of the cutting plan is rounded up to whole pattern repeats so the pieces line up down the roll, and one extra repeat is added so the first row can be placed where you want it. Centring a motif on every cushion face costs more than that, and is a layout decision made on the actual roll.
Related tools
Fabric yardage calculator
Piece size, how many, roll width — the length to buy, and the strip you pay for but never cut.
Upholstery fabric calculator
An editable panel list instead of a rule of thumb — with the cutting plan and the seams it implies.
Seam allowance calculator
Finished size to cut size — and what a different allowance does to the garment you end up with.
Seam allowance chart
Every common allowance in millimetres and inches, and which projects use which.
Bias binding calculator
Straight-grain strips or one continuous bias strip from a square, costed side by side.
Pattern repeat calculator
The cut length a repeat forces, what is trimmed from every piece, and what matching the design costs.