NULAYER › Answers › Does NULAYER run small? Sizing and between sizes
Does NULAYER run small? Sizing and between sizes
True to size, by the tape
The NULAYER bodysuit runs true to size for most wearers, with one condition: you size it by bust and waist against the chart, not by the size you buy in jeans or dresses. The bands are XXS–XS (US 0–2), S–M (US 4–10), L–XL (US 12–14) and 2XL–3XL (US 16–20), and each band lists a bust range and a waist range in inches and centimetres. Those are body measurements. If your bust and waist both land inside one band, that is your size, and the fit will be what the medium-firm description says.
The reason people ask whether it runs small is almost always one of two edge cases, and both have a rule.
The two edge cases
The first is the top of a band. If your bust or waist sits at the upper end of a range, go up one band. Our listing model is 5'7" and 170 lb, with a 38.9" bust, a 31.1" waist and 43.3" hips. Those numbers sit at the top of S–M, and she wears L–XL. That is the rule in action, not a sign that the garment runs small: at the top of a band, the larger band is the comfortable one.
The second is torso length. The straps are fully adjustable, and set for your torso they place the deep V and the crotch where they should be. But a long torso can use up the strap range, and if the straps at their longest still pull at your shoulders or lift the crotch, the size is too small, not the straps. A long torso often means going up a band even when bust and waist say otherwise.
Between sizes, and if the size is wrong
Between sizes, the smaller band gives maximum smoothing and the larger gives all-evening comfort. Choose by the event: a seated dinner or a full day is the larger band; a two-hour drinks party in a fitted dress can be the smaller. And if the Fit Finder picks your size and it is wrong, we replace it free, on top of Amazon's free 30-day refund or replacement. A wrong size costs you a few days, not the price. Sizing shows up at the closure too: if the hook-and-eye crotch closure pulls with the straps at their longest, that is the size, not the straps.
Which size: Measure bust and waist and read the chart; at the top of a band go up, between sizes choose by the evening, and a long torso usually goes up.
| Band | US | Bust (in) | Waist (in) |
|---|---|---|---|
| XXS–XS | 0–2 | 30–33.5 | 23–26 |
| S–M | 4–10 | 34–38.5 | 26.5–31 |
| L–XL | 12–14 | 39–41 | 31.5–34.5 |
| 2XL–3XL | 16–20 | 41.5–48 | 35–41.5 |
True to size for most wearers.
Between sizes: the smaller band for maximum smoothing, the larger for all-evening comfort.
Questions people ask
I am at the top of S–M. Which do I order?
L–XL. That is exactly our listing model's case: bust 38.9", waist 31.1", at the top of S–M, and she wears L–XL. At the top of a band, the larger band is the comfortable one.
Do the thong and the mid-thigh size the same?
Yes. One chart, by bust and waist, for both cuts. If you own one in S–M, order the other in S–M.
What if the Fit Finder gets my size wrong?
We replace it free, on top of Amazon's free 30-day refund or replacement. Measure bust and waist with a tape before you use it; the tool is only as good as the numbers.
Written by the NULAYER team and checked against the garment's tech pack. Last reviewed 2026-09-15. Facts on this page: 78% nylon, 22% spandex; machine wash cold, hang dry; designed and made in our own factory in zhejiang, china.