Fit calculators: ease and an elastic-waist skirt
Ease at bust, waist and hip from your measurements and a pattern's finished measurements, shown against the published ranges, and the cutting sizes for a simple elastic-waist skirt drafted from the hip.
Ease figures differ between pattern companies and extension guides, and the ease a pattern intends depends on its style. This page shows the numbers side by side and makes no call on whether a pattern will fit you. The finished measurements, then a tissue fit or a muslin, settle fit (Patterns and fit). Measurements are a sewing record, nothing more.
Ease from body and finished measurements
Ease is the difference between the finished garment and the body it covers. Enter your body measurements (from the measurements sheet, which fills these in) and the finished garment measurements printed on the pattern envelope or tissue for the size you are considering. Fill in only the pairs you have. Patterns and fit explains wearing ease and design ease.
The published ranges
| Source | Bust | Waist | Hip | What it describes |
|---|---|---|---|---|
| McCall Pattern Company fit brochure (1998) | 2 to 3 in | not given | 2 to 3 in | Minimum ease in finished measurements, before design ease, except close-fitted styles |
| NMSU Guide C-228 (2015) | 3 to 4 in | not given | 2 to 4 in | A fitted garment; the guide says ease varies with the pattern, fabric and preference |
| Tilly and the Buttons | 2 to 4 in (5 to 10 cm) | 1 to 2 in (2.5 to 5 cm) | 2 in (5 cm) | Typical minimum for woven garments; knits may have negative ease |
Assumptions
- Ease = finished measurement − body measurement. Simplicity's size chart page describes the same subtraction. Convention
- The finished measurements include both wearing ease and design ease (Simplicity's envelope guide says so), so a loose style shows far more than any minimum above. The envelope's fit description (close-fitting, fitted, semi-fitted, loose, very loose) says which kind of garment the pattern is.
- The ranges come from three publishers and do not agree. The calculator shows all three and gives no verdict. Test it
Elastic-waist skirt from the hip
A gathered rectangle with one seam, a casing and a hem, drafted from the hip measurement by Utah State University Extension's Youth Elastic Waist Skirt. It needs no pattern. Your project sews it if you chose a skirt.
Assumptions
- Circumference = hip × ease factor; fabric width = circumference + 2 × seam allowance for one center back seam; cut length = finished length + 2 3/4 in for 1 in elastic: a 1 1/2 in fold-down casing and a hem turned 1/4 in then 1 in. For other elastic widths the casing fold is the elastic width + 1/2 in (1/4 in clearance and 1/4 in for the raw-edge turn-under; our arithmetic from the figures below), and the calculator warns when an allowance you type is too small. All from Utah State's skirt, whose own example is a 30 in hip × 1.2 = 36 in + 1 1/4 in = 37 1/4 in of fabric width. Preference
- When the width needed is more than the fabric, the calculator splits it into the fewest equal panels that fit across the fabric (two or more), with one side seam per panel. Utah State also removes the selvages before cutting, because they can shrink more and pucker a seam.
- Casing at least 1/8 in wider than the elastic (Utah State) or at least 1/4 in wider (Oregon State's casings fact sheet). Convention
- Elastic is bought at least as long as the waist and then fitted by trying it on, with the ends overlapped and stitched. Neither extension source gives a fixed amount to cut off, so the calculator gives none. Test it
See it with the fictional cases
Marcus measures a 41 in hip. His pajama pattern's finished hip for size L is 48 1/2 in, so the ease tool shows 7 1/2 in of hip ease beside the three published ranges. The pattern describes a loose fit, and the figure is far above every minimum because most of it is design ease. The tool does not say whether that is right for him; a try-on of the basted pants does. His waist is 36 in: he bought 36 in of 1 in non-roll elastic and fitted it at 33 in on his own waist. All measurements are invented for the example.
Utah State's own skirt example, not a fictional case: a 30 in hip at the 1.2 factor needs 37 1/4 in of fabric width, which fits across 42 in fabric as one panel.
Record measurements and the finished figures in the measurements sheet; the ease column takes the result.