Nylon or Polyester Leggings: Which One Stretches More?

Short version — Nylon leggings almost always carry more spandex than polyester leggings from the same brand, by roughly five to nine percentage points. That makes them give more, not run bigger. The size chart stays the same either way, so the fiber line tells you how much forgiveness you are buying, not which letter to click.

"Nylon feels better, polyester lasts longer" is the version of this you hear in reviews. It is not wrong, but it is also not something you can check before you buy. The fiber percentages are, and they are printed on nearly every product page. So we read them.

What is actually in your leggings, nylon or polyester?

It depends almost entirely on the brand, and the split is sharper than we expected. Of 315 stretch-knit bottoms at CRZ Yoga that publish a fiber percentage, 275 — 87% — are nylon-based, usually written as polyamide. Only 37 are polyester-based. Baleaf runs the other way: of 112 stretch-knit bottoms, 76 are polyester-based and 33 are nylon.

The four brands we sampled by product page lean polyester. Girlfriend Collective builds its leggings from recycled water bottles, which is polyester — its Compressive High-Rise is 79% RPET and 21% spandex, and the lighter FLOAT is 90% RPET and 10%. Thirteen of the fourteen PopFlex bottoms we opened were 77% polyester and 23% spandex; the exception was a pair of jeans. All fourteen Senita pages we opened were polyester-based, between 72% and 80%, except one shorts style blended with nylon.

So the honest answer to "which is more common" is neither. It is a house decision, and it is consistent inside a house.

Which fiber carries more spandex?

This is the number that surprised us, because it repeated in three catalogs read independently.

Source: CRZ Yoga size guide and product listings; Baleaf product pages. Checked Sept. 19, 2026. Woven styles with no stretch fiber — golf pants, cargo capris, jeans — are excluded, because a 100% polyester golf trouser would drag the polyester average down for the wrong reason.

A third catalog we sampled, Bubblelime, came out the same way: of 24 randomly drawn bottoms, the 16 nylon-based pairs averaged 21.4% spandex and the 8 polyester-based pairs averaged 16.0%. Three catalogs, three times the same direction, with nylon landing near 21% each time.

Why it happens is not mysterious. Nylon is the more expensive shell fiber and tends to be used on the buttery, compressive styles a brand wants to sell hardest, and those styles need more elastane to hold their shape. Polyester shows up more on lightweight, printed and fleece-lined pairs where a lower stretch number is fine. The fiber is a proxy for the tier, not a cause.

Does more stretch fiber mean you need a different size?

No — and this is where the shopping advice usually goes wrong. More spandex means the fabric travels further before it pulls tight, so a pair that is a little snug on your hip has more room to give. It does not mean the pair was cut bigger.

CRZ Yoga makes the point for us. Its highest-stretch styles are a long way apart from its lowest: the Nakedfeel Light Pocket Shorts 6'' are 62% nylon and 38% spandex, and the Hugged Feel Legging 25'' is 64% and 36%. At the other end, the Matte Thermal Fleece Lined Pocket Legging 25'' is 83% polyamide and 17% Lycra, and the Butterluxe Super High Rise Legging 28'' is 81% and 19%. That is a spread from 17% to 38% stretch fiber inside one brand. All of them are sold against a single chart.

Why does one brand publish one chart for 7% to 38% stretch?

Because the chart describes your body, not the garment. Here is the whole CRZ Yoga bottoms chart, which covers every style above:

Source: CRZ Yoga size guide, bottoms table, checked Sept. 19, 2026.

Single numbers, no bands. A 28.5" waist is an M whether the pair is 17% Lycra or 38%. What changes between those two pairs is how far off 28.5" you can be and still be comfortable — and the chart never tells you that. We went through the same problem from the other direction in our look at how much spandex leggings actually contain.

How does a polyester brand's chart compare?

Girlfriend Collective, which is polyester throughout, publishes bands instead of points:

Source: Girlfriend Collective sizing and CRZ Yoga size guide, checked Sept. 19, 2026.

Take a 30" waist. Girlfriend puts you in the middle of its M. CRZ puts an M at 28.5" and an L at 30.5", so you are reaching for the L. Same body, different letter, and the fiber has nothing to do with it — it is the width of the band. We took two brands apart this way in our CRZ Yoga versus Girlfriend Collective comparison, and the general problem of landing between two numbers is covered in what to do when you are stuck between sizes.

What do the care labels say, and why do they disagree?

All six brands agree on cold water. They do not agree on the dryer, and the split runs along fiber lines only loosely.

Sources: CRZ Yoga, Baleaf, PopFlex, Girlfriend Collective and Senita product pages; Bubblelime product pages, 16 of 24 sampled specifying hand wash and 8 machine wash. Checked Sept. 19, 2026.

Two of the six tell you never to machine dry. Three tell you low heat is fine. That is not a small disagreement about a small thing: heat is what degrades elastane, and the pairs with the most elastane are the ones with the most to lose. If you own a 31% or 38% spandex pair, the conservative label is the one worth following regardless of who made it.

What about pilling?

We have no number for you, and neither does any brand we read. Not one of the six publishes an abrasion or pill-resistance rating, and we have not run a wear test, so anything we said here would be a guess dressed up as a finding. What the labels do tell you is where pilling starts: friction and heat. "Wash inside out," which Bubblelime prints and others imply, and "wash with like colors," which CRZ Yoga and Baleaf both print, are both about keeping the face of the fabric off zippers, towels and hooks.

So which should you buy?

Buy the fit and read the fiber line as a footnote, in this order:

• Measure first. Waist and the fullest part of the hip, both in inches, against the brand's own chart — the method is in how to measure for leggings.
• Check whether the chart uses points or bands. A point chart like CRZ Yoga's leaves you nowhere to land; a band chart like Girlfriend's absorbs half an inch.
• Then look at the spandex number. Under about 15% and the pair will feel structured and unforgiving; over about 25% and it will move with you but show more of what is under it.
• If the hip number is the one that does not fit, the fiber will not save you — that is a cut problem, covered in why leggings gap at the back.

One last thing worth saying plainly: none of the six brands changes its size chart when it changes fiber. We checked that directly in does fabric change the size chart, where one brand did publish two charts for two fabrics — the exception, not the rule. Brand-by-brand measurements are collected in our CRZ Yoga and Baleaf notes, and the letters themselves are compared in how five brands label the same body.

TL;DR — Nylon pairs carry about 21% spandex; polyester pairs carry 12% to 16%. That is a difference in give, not in size. Measure, read the chart's bands, and treat the fiber line as the last check rather than the first.