This comparison is really about denim, because the two brands don't even speak the same sizing language. GAP sells women's clothes in US numeric and alpha sizes and men's bottoms by waist in inches; Levi's sizes every pair of jeans by actual waist measurement — women's on a 24–34 scale, men's as W×L. That makes Levi's labels unusually honest, but it means a "GAP medium" and a "Levi's 28" can't be compared by label at all — only by body measurement.
Tops are even less apples-to-apples: Levi's published guide covers women's tops only, and Levi's is first and foremost a denim brand. So below we map GAP's women's sizes to Levi's jean sizes by body waist, line up the women's tops charts where they genuinely align, and explain how the men's waist-inch labels differ in practice.
The short answer
Neither runs smaller across the board — both are true to size in denim, and Levi's fit choice matters more than the brand
GAP jeans run mostly true to size in the waist, and Levi's runs true to size on paper too — men's Levi's actually fit about half an inch to an inch of body waist above the label number. The real differences are in the details: Levi's right size depends heavily on the fit and fabric (Ribcage and Wedgie run small, rigid denim has no give, the 511 is snug in the thigh), while GAP's quirks are inconsistent lengths and high-stretch washes that relax with wear.
Note the stretch advice points in opposite directions: at GAP, very stretchy washes are the ones to size down in; at Levi's, it's rigid denim that often needs a size up. Convert through your actual waist measurement — the table below shows that a GAP XXL and a Levi's 34 chart the exact same 37.75-inch waist — and then apply each brand's fit-specific rules.
GAP vs Levi's at a glance
| GAP | Levi's | |
|---|---|---|
| Sizing system | US numeric + alpha; men's bottoms by waist in inches | Waist-based: women's 24–34 scale, men's W×L in inches |
| Overall fit | True to size, leaning slightly generous | True to size on paper; varies by fit and fabric |
| Denim quirks | High-stretch washes relax with wear — consider sizing down | Rigid denim has no give — often needs a size up; Ribcage/Wedgie run small |
| Lengths | Inseams inconsistent — regular often runs short, long runs very long | You pick the exact inseam with the L number |
| Consistency | Fit can drift between items and seasons | Each fit (501, 511, Ribcage) has its own personality, but holds steady |
Women's jeans: GAP sizes mapped to Levi's sizes
Aligned by body waist measurement, not by label — the two brands use different sizing systems. GAP waists from its published chart; Levi's from its published US size guide.
| GAP size | GAP waist | Closest Levi's size | Levi's waist |
|---|---|---|---|
| XS (0–2) | 25.5" · 65 cm | 24–25 | 25.25" · 64 cm – 26.25" · 66.5 cm |
| S (4–6) | 26.5–27.5" · 67.5–70 cm | 25–26 | 26.25" · 66.5 cm – 27.25" · 69 cm |
| M (8–10) | 28.5–29.5" · 72.5–75 cm | 27–28 | 28.25" · 72 cm – 29.25" · 74.5 cm |
| L (12–14) | 30.75–32" · 78–81.5 cm | 29–31 | 30.25" · 77 cm – 32.75" · 83 cm |
| XL (16–18) | 33.75–35.75" · 85.5–91 cm | 32–33 | 34.25" · 87 cm – 35.75" · 91 cm |
| XXL (20) | 37.75" · 96 cm | 34 | 37.75" · 96 cm |
Women's tops side by side
GAP bust vs Levi's chest, both body measurements. The charts align letter-for-letter — Levi's single values sit inside GAP's ranges — but Levi's tops are a small slice of its range, so treat this as orientation, not the main event.
| Size | GAP bust | Levi's chest |
|---|---|---|
| XS | 32.5–33.5" · 82.5–85 cm | 33" · 84 cm |
| S | 34.5–35.5" · 87.5–90 cm | 35" · 89 cm |
| M | 36.5–37.5" · 92.5–95.5 cm | 37" · 94 cm |
| L | 39–40.5" · 99–103 cm | 39.5" · 100.5 cm |
| XL | 42–44" · 106.5–112 cm | 42.5" · 108 cm |
Men's jeans: what a Levi's waist label actually fits
Both brands label men's bottoms by waist in inches, so the labels look interchangeable — but Levi's states each labeled size fits a body waist about half an inch to an inch above the number, while GAP's guide says its jeans run mostly true in the waist.
| Labeled size | Levi's: fits body waist |
|---|---|
| W30 | 30.5–31" · 77.5–78.5 cm |
| W31 | 31.5–32" · 80–81.5 cm |
| W32 | 32.5–33" · 82.5–84 cm |
| W33 | 33.5–34" · 85–86.5 cm |
| W34 | 34.5–35" · 87.5–89 cm |
| W36 | 36.5–37.5" · 92.5–95.5 cm |
| W38 | 38.5–39.5" · 98–100.5 cm |
Switching between GAP and Levi's
- Convert by body waist, never by label: a GAP M (28.5–29.5" waist) lands at Levi's 27–28, and a GAP XXL charts the same 37.75" waist as a Levi's 34.
- Flip your stretch instincts when you switch: size down in GAP's very stretchy washes, size up in Levi's rigid denim — and up one (sometimes two) in Ribcage and Wedgie fits.
- Lengths work differently: GAP's regular inseam often runs short, so check the inseam options; at Levi's just order your real inseam as the L number.
- Men moving from GAP to Levi's: your usual waist number is a fine starting point — Levi's labels actually fit half an inch to an inch of extra body waist, so don't size up preemptively.
Measurements are based on each brand's published size charts and may vary by garment, fabric, and region. For the full charts and fit notes, see the GAP size guide and the Levi's size guide.
GAP vs Levi's sizing FAQs
Which runs smaller, GAP or Levi's jeans?
Neither, as a brand: GAP jeans run mostly true to size in the waist, and Levi's labels are real waist measurements — men's even fit slightly above the number. The size-up cases at Levi's are fit-specific (Ribcage, Wedgie, rigid 501s); at GAP the trap is high-stretch washes relaxing with wear.
What Levi's size am I if I wear a GAP medium?
A GAP women's M covers a 28.5–29.5" waist, which maps to a Levi's 27 or 28 on Levi's chart. If you're choosing a rigid fit like the original 501, Levi's own guidance points to a size up from there, since raw denim has no give.
Do GAP and Levi's men's waist sizes mean the same thing?
Almost. Both label men's bottoms by waist in inches, but Levi's states each labeled size actually fits a body waist about half an inch to an inch above the number — a W32 fits a 32.5–33" waist — while GAP's denim runs mostly true to the label in the waist.
Can I compare GAP and Levi's tops sizes?
Only loosely. Levi's published guide covers women's tops, and there the charts align letter-for-letter with GAP — a Levi's M charts a 37" chest, inside GAP M's 36.5–37.5" bust range. There's no men's tops chart in Levi's guide, so for menswear stick to denim comparisons.
Will Levi's shrink more than GAP jeans?
Usually not — most modern Levi's are preshrunk and barely shrink washed cold. The exception is rigid Shrink-to-Fit 501s, which Levi's says need about 1 inch extra in the waist and 3 in length if you'll machine-wash them. GAP's issue runs the other way: stretchy washes loosen rather than shrink.
