Tool
Circle skirt calculator: waist radius and fabric
Choose how full the skirt should be, then type your waist, the length and the width of the fabric you are buying. The radius, the yardage and a to-scale cutting layout update as you type. Free, no account, nothing saved: it runs in your browser.
Your full circle skirt
Waist radius
4½ in
cut at 3⅞ in for the waist seam
Fabric to buy
1⅝ yd
55⅛ in of 60 in fabric (1.5 m)
Pieces
1 piece
no side seam: cut an opening for a zip, or use an elastic waist
Show the math
- Waist radius. 28 in ÷ 2π (6.283) = 4½ in. That circle's edge is your waist seam.
- Cut the waist. 4½ in − ⅝ in seam allowance = 3⅞ in. Cut the waist curve there; the seam lands back on the radius.
- Cut the hem. 4½ in + 22 in length + ½ in hem = 27 in, measured from the same centre point.
- Lay it out. Each quarter needs a square 27⅝ in on a side (the hem radius plus ⅝ in for a side seam). 60 ÷ 27⅝ = 2.18, so 2 across; 4 quarters ÷ 2 = 2 rows × 27⅝ in = 55⅛ in.
- Buy. Rounded up to the next ⅛ yard: 1⅝ yd. Add extra for a waistband, for a print that has to match, and for prewashing if your fabric shrinks.
Narrower than 55⅛ in, it has to be cut in more pieces. The hem is 166¼ in round, which is what you will be hemming.
Circle skirt waist radius chart
The waist (stitching) radius for each fullness, straight from the formula. Cut the waist curve one seam allowance smaller than the number here.
| Waist | Full circle | Three-quarter circle | Half circle | Quarter circle |
|---|---|---|---|---|
| 22 in (55.9 cm) | 3½ in (8.9 cm) | 4⅝ in (11.9 cm) | 7 in (17.8 cm) | 14 in (35.6 cm) |
| 24 in (61 cm) | 3⅞ in (9.7 cm) | 5⅛ in (12.9 cm) | 7⅝ in (19.4 cm) | 15¼ in (38.8 cm) |
| 26 in (66 cm) | 4⅛ in (10.5 cm) | 5½ in (14 cm) | 8¼ in (21 cm) | 16½ in (42 cm) |
| 28 in (71.1 cm) | 4½ in (11.3 cm) | 6 in (15.1 cm) | 8⅞ in (22.6 cm) | 17⅞ in (45.3 cm) |
| 30 in (76.2 cm) | 4¾ in (12.1 cm) | 6⅜ in (16.2 cm) | 9½ in (24.3 cm) | 19⅛ in (48.5 cm) |
| 32 in (81.3 cm) | 5⅛ in (12.9 cm) | 6¾ in (17.2 cm) | 10⅛ in (25.9 cm) | 20⅜ in (51.7 cm) |
| 34 in (86.4 cm) | 5⅜ in (13.7 cm) | 7¼ in (18.3 cm) | 10⅞ in (27.5 cm) | 21⅝ in (55 cm) |
| 36 in (91.4 cm) | 5¾ in (14.6 cm) | 7⅝ in (19.4 cm) | 11½ in (29.1 cm) | 22⅞ in (58.2 cm) |
| 38 in (96.5 cm) | 6 in (15.4 cm) | 8⅛ in (20.5 cm) | 12⅛ in (30.7 cm) | 24¼ in (61.4 cm) |
| 40 in (101.6 cm) | 6⅜ in (16.2 cm) | 8½ in (21.6 cm) | 12¾ in (32.3 cm) | 25½ in (64.7 cm) |
| 42 in (106.7 cm) | 6⅝ in (17 cm) | 8⅞ in (22.6 cm) | 13⅜ in (34 cm) | 26¾ in (67.9 cm) |
| 44 in (111.8 cm) | 7 in (17.8 cm) | 9⅜ in (23.7 cm) | 14 in (35.6 cm) | 28 in (71.1 cm) |
| 46 in (116.8 cm) | 7⅜ in (18.6 cm) | 9¾ in (24.8 cm) | 14⅝ in (37.2 cm) | 29¼ in (74.4 cm) |
Inches rounded to the nearest ⅛, centimetres to the nearest millimetre. For a pull-on elastic waist, read the row for your hip measurement instead.
How much fabric for a circle skirt
Yards to buy for a 28-inch waist at the calculator's allowances (⅝ in waist and side seams, ½ in hem), on the two fabric widths Treasurie names as usual: 44 and 60 inches. Enter your own waist above for your numbers.
| Length | Full circle, 44 in fabric | Full circle, 60 in fabric | Half circle, 44 in fabric | Half circle, 60 in fabric |
|---|---|---|---|---|
| 18 in | 2⅝ yd | 1⅜ yd | 1⅝ yd | ⅞ yd |
| 22 in | 3⅛ yd | 1⅝ yd | 1⅞ yd | 1⅞ yd |
| 26 in | 3⅝ yd | 3⅝ yd | 2⅛ yd | 2⅛ yd |
| 30 in | 4 yd | 4 yd | 2¼ yd | 2¼ yd |
“Too long” means even a quarter of the skirt is wider than the fabric: go wider, go shorter or cut more panels. Add fabric for a waistband, pattern matching and prewash shrinkage.
How the calculator works
- The waist is part of a circle. A circle's edge is 2π times its radius. A full-circle skirt's waist is that whole edge, so radius = waist ÷ 2π. A half circle's waist is half the edge, so radius = waist ÷ π; a quarter circle, waist ÷ ½π. These are the formulas Minerva Patterns and Omni Calculator publish.
- Two cutting lines from one centre. The waist cut sits one seam allowance inside the radius; the hem cut sits at the radius plus the length plus the hem allowance. The Polka Dot Chair adds the waist radius to the length in the same way.
- Quarters on a grid. Every circle skirt is quarter circles: four for a full circle, three for three-quarter, two for a half, one for a quarter. Each needs a square of fabric the hem radius plus a side seam allowance on a side. The calculator fits as many squares across the fabric as it can, stacks the rest down the length and joins quarters that meet at a corner into one piece. A full circle that does not fit across is cut as two half circles, the layout Treasurie and Minerva Patterns describe.
- Rounded up, not down. The length is rounded up to the next ⅛ yard or 10 cm. The layout adds a seam allowance even where an edge could sit on a fold, so it errs a few inches long. With the defaults (28 in waist, 22 in long), a full circle takes 1⅝ yd of 60-inch fabric and 3⅛ yd of 44-inch.
- Hang it before you hem. Parts of the hem are on the bias and stretch. Minerva Patterns says hang it at least 24 hours, Simply Sewing says overnight, then level the hem from the floor.
For a skirt with other pieces (a waistband, pockets, a lining), list them in the fabric yardage calculator and add that to the skirt's yardage.
What you mark and cut a circle skirt with
The top pick on each of our shelves, at today's price.
Marking & Measuring · Dritz 673-60 marking pen$4.97 4.6 out of 5 stars · 1,767 ratings
A tape measure pinned at the centre swings the waist and hem curves; chalk marks them.
Fabric Scissors · Wteehn 8" Heavy Duty Fabric Scissors$9.89 4.8 out of 5 stars · 1,646 ratings
Long, smooth cuts around a curve that is several feet of hem.
Pins & Fabric Clips · MumCraft Multipurpose Sewing Clips$5.69 4.8 out of 5 stars · 45,244 ratings
Holds the folded layers together so both cut the same.
Researched, not hands-on tested. We may earn a commission; it never changes a pick.
Frequently asked
How do you calculate the waist radius for a circle skirt?
Divide your waist measurement by 2π (about 6.28) for a full circle, by π (about 3.14) for a half circle, and by half of π (about 1.57) for a quarter circle. A 28-inch waist gives a full-circle radius of about 4½ inches. Minerva Patterns and Omni Calculator publish the same formulas.
How much fabric do I need for a circle skirt?
It depends on your waist, the length and the fabric width, because the hem radius (waist radius plus length plus hem) decides how many quarter circles fit across. A full circle, 28-inch waist and 22 inches long takes about 1⅝ yards of 60-inch fabric but about 3⅛ yards of 44-inch fabric, by this calculator's layout.
Can you make a full circle skirt from 44 or 45 inch fabric?
Yes, in two half circles joined with side seams, as long as the hem radius plus a seam allowance is no wider than the fabric. That cuts a knee-length skirt for most waists; a much longer full circle needs wider fabric or more panels. Treasurie and Minerva Patterns both cut full circles as two halves for this reason.
What is the difference between a full, half and quarter circle skirt?
How much of a circle the skirt opens out to. A full circle makes the most swing and uses the most fabric, a half circle is a moderate flare, and a quarter circle is close to an A-line with the least fabric. The waist is the same length in all three; only the waist radius changes.
Do you subtract seam allowance from the waist radius?
Cut the waist curve a seam allowance smaller than the radius, so the stitching line lands back on it. Omni Calculator builds a 2 cm subtraction into its formula for this. This calculator shows both numbers: the radius and the cutting radius.
Why is my circle skirt hem uneven?
Parts of a circle skirt's hem fall on the bias and stretch under their own weight. Minerva Patterns says to hang the skirt for at least 24 hours and Simply Sewing says overnight, then re-level the hem from the floor before you finish it.
Sources
Last checked: . The radii and yardage are arithmetic; these pages are where the formulas and the cutting conventions come from.
- Minerva Patterns: Drafting a circle skirt and calculating the radiusWaist ÷ 2π for a full circle, ÷ π for a half, ÷ half of π for a quarter; a full circle rarely fits standard fabric width, so cut two half circles; hang the cut skirt at least 24 hours and re-level the hem from the floor.
- Omni Calculator: Circle Skirt CalculatorSubtracts 2 cm (about 0.8 in) of seam allowance from the waist radius and adds 2 cm of hem to the outer radius; gives the ¾-circle formula as 4/3 × waist ÷ 2π.
- Treasurie: How to Make a Circle Skirt (Easiest Beginner Tutorial)Fabric usually comes 44 or 60 inches wide; a full circle is unlikely to fit the width, so cut two semicircles joined at the sides; 5/8 inch side seams.
- The Polka Dot Chair: Learn How to Sew a Circle SkirtA half circle skirt: add the waist radius to the skirt length for the cutting radius, fold 44 inch fabric across its width to cut it, and hem with a scant 1/4 inch double fold.
- Simply Sewing: How to make a circle skirt1 cm (3/8 in) seam allowance on the waist curve and straight edges; fabric width limits how long the skirt can be; hang the skirt overnight and level the hem before finishing.