A fabric yardage calculator answers the question that decides whether a project finishes: how much do I actually buy? Fabric is sold by length off a bolt of fixed width, and pieces are cut in two dimensions, so the answer is never simply total area divided by width. It depends on how many of your pieces fit side by side across the usable width, how many rows that forces, and whether a printed pattern has to line up. Get it wrong by half a yard and the dye lot you needed has gone.
This is one of the free tools Arb Digital maintains, and it is a cutting-layout calculator rather than an area calculator. It differs from every adjacent tool on this site in one specific way: it lays rectangular pieces across a fixed bolt width and counts the rows. The square footage calculator gives you an area with no width constraint at all, and the wallpaper calculator handles drops on a wall rather than pieces on a bolt.
What This Fabric Yardage Calculator Does
Give it the finished size of one piece, how many you need, the usable width of the fabric and any pattern repeat. It returns the yardage to buy, rounded up to the increment the shop will actually cut, plus the metre equivalent, the number of pieces that fit across the width, the number of rows that requires, how efficiently the layout uses the cloth, and what the whole thing costs.
The efficiency figure is the one worth watching. It compares the total area of your pieces against the area of fabric you are buying, and on an awkward combination of piece width and bolt width it can drop below 50%. That is the signal to change something — reorient the piece, choose a different bolt width, or nest two different piece sizes in the same row.
The usable width dropdown deliberately quotes numbers below the nominal bolt width. A "44 inch" quilting cotton is nominally 44 inches from edge to edge but the selvedges eat an inch or so on each side, and the last half inch of true cloth is often distorted. Cutting to the nominal width is the single most common way a layout that worked on paper fails on the table.
How to Use It
- Measure the largest piece with seam allowances included. Pattern pieces from an envelope already include them; drafted pieces usually do not.
- Count every piece. A piece cut on the fold uses the width of two, and linings, facings, pockets and bindings all consume yardage.
- Choose the usable width, not the label width. The dropdown allows for selvedges; use Custom if you have measured the bolt yourself.
- Enter the pattern repeat if the print must match. Stripes, plaids, large florals and directional prints all need it; small tossed prints usually do not.
- Set a waste allowance. Ten per cent is a reasonable default for straightforward pieces; go to twenty for curves, bias cutting or a fabric that may shrink.
The Formula / How It's Calculated
The layout is worked out in three steps, and the first one is integer division, which is why the answer jumps rather than scales smoothly.
Pieces across = floor(usable width ÷ piece width). Rows = ceiling(quantity ÷ pieces across). Length = rows × cut length, where the cut length is the piece length rounded up to a whole number of pattern repeats when a repeat is set. Add the waste allowance, divide by 36 to get yards, and round up to the shop's cutting increment.
Worked example, checked by hand. Six pieces at 20 × 30 inches on 42 inches of usable width, no pattern repeat, ten per cent waste. Pieces across = floor(42 ÷ 20) = 2. Rows = ceiling(6 ÷ 2) = 3. Length = 3 × 30 = 90 inches. Adding ten per cent gives 99 inches, which is 2.75 yards — and 2.75 is already a clean eighth, so the answer is 2¾ yards, or 2.51 metres. At $12 a yard that is $33.00. Layout efficiency is the six pieces' 3,600 square inches against the 99 × 42 = 4,158 square inches purchased, or 87%.
Now add a 12 inch pattern repeat. The cut length becomes ceiling(30 ÷ 12) × 12 = 36 inches. Three rows is 108 inches, plus ten per cent is 118.8 inches, or 3.30 yards, rounding up to 3⅜ yards. The repeat cost you five-eighths of a yard on a small project, and that penalty grows linearly with the number of rows.
Why Pattern Repeat Costs More Than People Expect
A pattern repeat is the distance along the fabric before the design starts again. To make a print match across a seam, every piece has to begin at the same point in the repeat, which means each cut length is rounded up to a whole number of repeats. The waste is the gap between your actual piece length and the next repeat boundary, and it is paid on every row.
The worst case is a piece length just over a repeat boundary. A 30 inch piece on a 12 inch repeat wastes 6 inches per row — 20% of the piece. A 25 inch piece on the same repeat wastes 11 inches per row, or 44%. Shifting a design by two inches to land at 24 inches would eliminate the waste entirely. This is why upholstery quotes ask for the repeat before they quote yardage at all.
Half-drop repeats, where alternate columns are offset by half the repeat vertically, make it worse again, and large-scale prints on curtains often need a full extra repeat per drop to guarantee the match. The same arithmetic drives wall coverings, which is why the wallpaper calculator asks the same question — the geometry of matching a repeat is identical whether the material hangs on a wall or is sewn into a cushion.
Grain, Nap and the Pieces You Cannot Rotate
The calculator assumes every piece is laid the same way up. That assumption is often forced on you rather than chosen. Woven fabric has a lengthwise grain that barely stretches and a crosswise grain that gives a little, and garments hang correctly only when the grainline runs as the pattern specifies. Rotating a piece ninety degrees to fit the bolt better will make it drape differently and, on a fitted garment, will make it fit differently.
Nap is the second constraint. Velvet, corduroy, brushed fleece and many satins reflect light differently depending on direction, so pieces laid head to toe will read as two different colours in the finished item. Directional prints have the same problem for a more obvious reason. If your fabric has nap or a directional print, every piece must run the same way, no rotating and no nesting upside down, and a "with nap" layout typically needs somewhere between ten and twenty-five per cent more fabric than a layout without that restriction.
Bias cutting is the exception that breaks the model entirely. A piece cut at forty-five degrees to the grain needs a square of fabric with a side roughly equal to the piece's diagonal, so bias-cut skirts and bindings consume far more than their finished area suggests. For those, treat this calculator's answer as a floor and add generously.
Shrinkage, Prewashing and Buying Once
Natural fibres shrink when they are first washed, and the shrinkage is usually not equal in both directions — cotton typically loses more along the length than across the width. If you prewash before cutting, which you should for anything that will be laundered, the fabric you cut from is smaller than the fabric you bought. Building that into the waste allowance rather than discovering it on the table is the difference between a comfortable cut and a scramble.
Fibre content determines how much to allow, and it is one of the things a garment label must legally disclose. The Federal Trade Commission's guide, Threading Your Way Through the Labeling Requirements Under the Textile and Wool Acts, sets out what fibre content and country-of-origin information has to appear on textile products sold in the United States — which is why the bolt end is the right place to check what you are actually buying before you estimate how it will behave.
Buy the whole amount in one transaction as well. Dye lots vary, and two cuts of the same nominal colour bought weeks apart can be visibly different under daylight. If the project might grow, buy the extra now; fabric keeps, and the same bolt will not.
Working in Metres Instead of Yards
Most of the world sells fabric by the metre off bolts measured in centimetres, and mixing the two systems is a reliable way to end up short. A yard is exactly 0.9144 metres, a definition fixed by international agreement and reflected in the NIST guidance on SI units, so a metre is about ten per cent longer than a yard. Ask for three metres when you meant three yards and you have overbought by roughly a third of a yard; ask for three yards when you meant three metres and you are short by the same.
Bolt widths convert awkwardly too. The common 44 inch bolt is 111.8 cm, usually sold as 110 cm; the 60 inch bolt is 152.4 cm, sold as 150 cm. Those rounded-down metric widths are genuinely narrower than their imperial names suggest, so re-run the layout at the true width rather than assuming they are the same cloth. The cm to inches converter handles the conversion, and the clothing size converter covers the related problem of sizing across systems.
Arb Digital's free tools cover material costing, pricing and margin as well as the maths behind the making, and our team is happy to help with the commercial side.
Browse Free Tools Talk to Arb DigitalCommon Mistakes to Avoid
- Using the nominal bolt width — selvedges and distorted edges mean the usable width is one to two inches narrower than the label says.
- Forgetting seam allowances — a drafted piece measured at its finished size will be short on every edge once the seams are taken.
- Ignoring nap and directional prints — pieces laid in opposite directions read as different colours, and a with-nap layout needs meaningfully more fabric.
- Treating a pattern repeat as a rounding detail — the repeat penalty is paid on every row, so it scales with the size of the project.
- Buying in two trips — dye lots differ, and a second cut of the same colour will not necessarily match the first.
Related Free Tools From Arb Digital
Use the square footage calculator when you need a plain area with no width constraint, the wallpaper calculator for the same repeat-matching problem on walls, the cm to inches converter to work between imperial and metric bolts, the clothing size converter for garment sizing across systems, and the unit price comparison calculator to compare fabric priced by the yard against fabric priced by the metre. The full library is in the free online tools hub.
Frequently Asked Questions
On 42 inches of usable width, two pieces fit across, so six pieces need three rows of 30 inches, or 90 inches. With a ten per cent waste allowance that is 99 inches, which is two and three-quarter yards.
Usable width is the cloth you can actually cut from, excluding the selvedges on both edges and any distorted fabric next to them. A bolt sold as 44 inches typically gives about 42 inches of usable width.
Each cut length has to be rounded up to a whole number of repeats so the print matches across seams. That rounding waste is paid on every row, so the penalty grows with the number of rows rather than being a one-off addition.
Around ten per cent covers straightforward rectangular pieces on a stable woven fabric. Twenty per cent is more realistic for curved pieces, bias cutting, slippery fabrics or anything that will shrink when it is prewashed.
Only if the grainline and the fabric allow it. Rotating a piece changes how it drapes and stretches, and on napped or directional fabrics it changes the apparent colour, so the layout has to keep every piece running the same way.
A yard is exactly 0.9144 metres, so a metre is roughly ten per cent longer than a yard. Metric bolts are also usually sold at rounded widths such as 110 cm or 150 cm, which are narrower than the 44 and 60 inch bolts they replace.
For anything that will be laundered, yes, because natural fibres shrink on first wash and usually shrink more along the length than across the width. Prewashing before cutting means the pieces you cut are the size they will stay.
This tool estimates a straightforward rectangular cutting layout. Complex pattern pieces, bias cutting, matching across multiple different piece sizes and fabric-specific shrinkage all change the answer, so treat the figure as a minimum and confirm against your own layout before cutting.
