How Much Fabric Do You Need for Bunting? A Yardage Explainer
Bunting is one of those projects that feels generous and simple right up until you are standing at the cutting table with a half-metre of fabric and twenty flags to make. The good news is that the math behind it is genuinely easy once you know the order to do it in. Work out your flag size, count your flags, then let the fabric width tell you how many strips you need. Here is how that plays out in practice.
Decide the Flag Size Before Anything Else
Flag size drives every other number, so pick it first and write it down. The classic bunting triangle is roughly 6 inches wide and 8 inches tall, but there is no rule that says you have to use it.
- Mini (4 in wide x 5 in tall): cake bunting, small shelves, party picks.
- Small (5 in x 6.5 in): doorways, mantels, kids' rooms.
- Standard (6 in x 8 in): the workhorse size for walls and garden parties.
- Large (8 in x 10 in): big rooms, marquees, photo backdrops.
- Bold (10 in x 12 in): outdoor events where it needs to read from a distance.
Those are finished sizes. If you are making double-sided flags that get sewn right sides together and turned, add your seam allowance twice to each measurement. A quarter-inch seam on each side means a finished 6 x 8 flag is cut at 6.5 x 8.5 inches. If you are cutting single-layer flags with pinked or zigzagged edges, cut exactly to size. This single distinction catches more people out than any other part of the project.
Count Your Flags From the Length You Want to Cover
A garland is not the same length as the wall. Flags sit along a tape with small gaps, and you need tails at each end for tying. A straightforward way to size it:
- Measure the space you want to dress.
- Add slack if it will swag. A garland hung in gentle dips needs roughly half again the straight-line distance, so 12 feet of wall becomes about 18 feet of bunting.
- Add 18 to 24 inches of extra tape at each end for tying.
- Divide the flag-bearing length by your flag width plus gap. A 6-inch flag with a 2-inch gap occupies 8 inches of tape.
For a 12-foot run (144 inches) with 36 inches of tails, you have about 108 inches of flag space. At 8 inches per flag, that is 13 or 14 flags. Round up to 14 and you have a small cushion for a mistake.
The Strip Method, and Why It Saves So Much Fabric
Most people picture cutting one triangle at a time out of a rectangle, which wastes a startling amount of cloth. Instead, cut a strip of fabric as tall as your flag and cut alternating triangles along it, one pointing up and the next pointing down, with their slanted sides touching. Each pair shares an edge, so you are barely losing anything.
The calculation for a single strip
Say your cut flag is 7 inches wide and 9 inches tall, and your fabric is 44 inches wide with 42 usable inches after trimming the selvedges. Cut a strip 9 inches tall and 42 inches long. The first triangle takes a full 7 inches. Every triangle after that advances only half the width, so 3.5 inches each. That means 7 + (n - 1) x 3.5 must stay under 42, which gives you 11 triangles per strip.
Eleven triangles out of a 9-inch strip is the number worth remembering. For 20 single-sided flags you need two strips, so 18 inches of fabric. For 20 double-sided flags you need 40 triangles, which is four strips, so 36 inches — a yard of standard quilting cotton. That is a genuinely useful figure to carry in your head.
Two things change the number. Wider fabric means more triangles per strip, and since strip height stays the same, you need fewer strips and less total yardage. Quilting cotton at 44 inches is the tightest case; 60-inch home decor fabric is noticeably more generous. Narrower flags get you even more per strip, because each triangle advances by half its own width.
Double-Sided Bunting Doubles the Triangles
If both sides of the bunting will be visible, every flag needs two triangles sewn right sides together, then turned and pressed. Quietly, this is the single biggest multiplier in the whole project — double the triangles, double the strips, double the yardage.
You do not have to double your expensive fabric, though. Use the print on the front and a plain cotton, muslin or lining on the back. Nobody sees the back face of a hanging flag from the front, and if the garland twists in the breeze, a solid colour reads as intentional. Just check the main fabric is opaque enough: pale, thin cotton backed with a dark lining will look muddy from the front. Hold the two layers together against a window before you cut 40 triangles from them.
Directional Prints Need Extra Yardage
Nesting triangles point-up, point-down only works when the fabric does not care which way it faces. Small florals, dots, solids and most blenders are fine. Stripes, plaids, novelty prints with animals or text, and anything with a distinct top and bottom are not. Turn half your flags upside down and it will look like a mistake, not a design choice.
For those fabrics, cut every triangle in the same orientation. That doubles the length each triangle occupies along the strip, so plan on roughly twice the yardage you calculated. The alternative is to choose a print with an obvious repeat and cut in matched pairs, but that is fiddly work for a decoration that will be seen from six feet away.
A Quick Yardage Checklist
- Finished flag size, and whether you are cutting with seam allowance.
- Number of flags, rounded up.
- Triangles needed: the flag count, or double it for double-sided.
- Triangles per strip, using the half-width rule and your usable fabric width.
- Strips needed, rounded up.
- Strips x flag height = total inches. Divide by 36 for yards.
- Add 10 percent for pre-washing shrinkage, selvedge trimming and one bad cut.
- Add tape: total flag length plus gaps plus 36 inches of tails.
Don't Forget the Tape, and Buy a Little Extra
The flags are only half the supply list. Bias binding or a wide ribbon runs the full length of the garland, and you need enough to hold every flag plus the tails. Twenty standard flags with 2-inch gaps comes to 180 inches, and with tails that is six yards of tape. Pre-packaged double-fold bias tape is usually sold in three-yard packs, so buy two. Making your own bias tape from the same fabric is lovely, but it adds yardage to your total — roughly the length of tape you need, cut in strips and joined.
Buy half a yard more than the math says. Not because the math is wrong, but because cutting 40 triangles by hand rarely goes perfectly, and running out of a print mid-project is the kind of problem that turns a pleasant afternoon into a trip to the shop. Keep the offcuts, too. They make excellent tiny bunting for a card, a jar or a cake, and they are the cheapest way to test your seam allowance before you commit to the real thing.
