Fit, measuring and alterations · 8 October 2026 · 3 min read
How to measure an elastic waist on trousers you own
How to measure elastic waist trousers that fit: the relaxed and stretched readings, and which one a tailor needs for elastic, drawstring and half-elastic waists.
InspirationRelaxed and stretched: take both
Lay the trousers flat and measure straight across the top of the waistband without pulling it: that is the relaxed reading. Then stretch the waistband gently until the fabric lies flat and the elastic starts to resist, and measure across again: that is the stretched reading. Double both figures. A tailor uses the relaxed one to set the length of the elastic and the stretched one to check the trousers will pass over your hips.
Our guide to measuring clothes that fit you covers garment measurements in general. An elastic waist is the one place where a single flat number is not enough.
Taking the readings without errors
Most mistakes come from stretching too far, or from measuring a waistband that has gone tired. A few habits keep the figures honest:
- Smooth the trousers on a table with the side seams at the edges, not rolled to the front or back.
- Measure along the very top edge of the waistband, from fold to fold.
- For the stretched reading, hold one side still and pull the other only until the gathers disappear. If the stitching cracks or the elastic thins, you have gone too far.
- Write each figure with a note: flat, relaxed, doubled; flat, stretched, doubled.
- Measure your own waist where the trousers sit, and your hips, and send those too.
Which number for which waist
Trousers close in different ways, and each needs something slightly different from you:
- Full elastic: both readings. The relaxed figure is usually a little smaller than your waist so the band grips; the stretched figure must clear your hips with room to spare.
- Drawstring (nala): the relaxed reading means little, because the cloth is simply gathered up. Untie it, open the waist out flat and measure the full width of fabric across, then double it. Add your waist where the shalwar sits.
- Half-elastic, flat front with elastic back: measure the flat front straight across between the side seams, then the back relaxed and stretched as for full elastic.
- Elastic with a drawstring as well: treat it as full elastic. The cord only tightens it a little further.
When the pair you own is not quite right
If the trousers slip down, the relaxed figure is too big for you; if they leave a mark, it is too small. Say which, and by roughly how much, rather than adjusting the numbers yourself. Old elastic loses its grip, so a waistband that feels loose may be a tired pair rather than the wrong size. Mention its age, and rely more on your body waist measurement.
The waist works with the rise and length too, which our trouser fit article explains. For the other trouser figures, see the trouser size guide, and for the classic gathered style, the shalwar page.
Sending trousers you like as a guide
Write the readings, with their labels, in the notes on your order. If you are sending your own fabric to be stitched through Stitching Only, we confirm what we need before you post anything; start with a Stitching Only quote. The waist style is agreed in writing with the rest of the design before cutting.
Common questions
Should I double the flat waist measurement?
Yes, because a flat measurement covers only the front half of the waistband. Double it and say that you have, so nobody doubles it a second time.
How far should I stretch an elastic waistband to measure it?
Only until the gathers lie flat and the elastic starts to push back. Pulling harder overstates the stretch, and the new waistband may then struggle over your hips.
Do I need my hip measurement for elastic trousers?
Yes. An elasticated waist has no opening, so the stretched waistband has to pass over the fullest part of your hips. The hip figure lets the tailor check that it will.