Jeans Size to Leggings Size: A 27 Is a 28-Inch Waist, and Here's Where That Lands
- Madewell's denim chart puts a size 27 jean on a 28" waist and a 38" hip. The number on the jean is not your waist in inches.
- On that body, Girlfriend Collective and PopFlex both land on the line between S and M. Sweaty Betty sits between its S (27") and M (29").
- A "UK 8" means a 28" waist on Madewell's conversion tab and a 25" waist on Sweaty Betty's chart.
Quick answer — Don't convert the jean number. Convert the body it was cut for. On Madewell's chart a denim size is roughly your waist minus one inch: a 27 fits a 28" waist, a 30 fits a 31.5" waist. Take that waist to a legging chart. For a 27, that is S or M at Girlfriend Collective and PopFlex. For a 30, it is L at both.
This is the most common shortcut people try when they shop for leggings: "I'm a 27 in jeans, so what am I in leggings?" It works, but only if you take one step through the actual inches. Below are the charts, side by side, for denim sizes 23 to 33 and plus sizes 14W to 18W.
What waist does a jeans size actually mean?
Less than the number says, at least on a denim chart that prints body measurements. Madewell lists a waist and hip for every denim size. From 23 to 28, each size is exactly one inch above its label. From 28 up, the steps between sizes widen to 1.25"–1.75".
| Madewell denim size | Body waist | Body hip |
|---|---|---|
| 23 | 24" | 34" |
| 24 | 25" | 35" |
| 25 | 26" | 36" |
| 26 | 27" | 37" |
| 27 | 28" | 38" |
| 28 | 29" | 39" |
| 29 | 30.25" | 40.25" |
| 30 | 31.5" | 41.5" |
| 31 | 33" | 43" |
| 32 | 34.5" | 44.5" |
| 33 | 36.25" | 46.25" |
| 14W | 37" | 47" |
| 16W | 39" | 49" |
| 18W | 41" | 51" |
Source: Madewell Denim Size Chart, Measurements tab (madewell.com/Denim-SizeChart.html), read Sept. 27, 2026. The chart continues to 28W (51" waist, 61" hip).
The hip runs a steady 10" above the waist on every row. Keep that in mind, because legging charts do not all assume the same gap; we measured that drop across brands in why leggings gap at the back.
What size leggings is a size 27 jean?
A 28" waist and a 38" hip. Here is where that lands on three legging charts we read today:
- Girlfriend Collective: S runs 26"–28" at the waist and M runs 28"–30.5". A 28" waist sits exactly on the line. The 38" hip sits inside S (36"–39").
- PopFlex: S is 26"–28", M is 28"–31". Same line. The 38" hip is also the S/M boundary (36"–38" and 38"–40").
- Sweaty Betty: prints one number per size. S is 27", M is 29". A 28" waist is halfway. The 38" hip matches S exactly.
So a 27 is a small with a waist that could take a medium. Girlfriend's own FAQ says to size down for a more compressive fit and up for a more relaxed one. Our between-two-sizes guide explains why we'd let the waistband make the call.
What's the full jeans-to-leggings chart?
Each row takes the Madewell body waist from the table above and finds it on each legging chart. Where a waist sits on a boundary, both sizes are listed.
| Denim size (waist) | Girlfriend Collective | PopFlex | Sweaty Betty | Bubblelime BWWB009 |
|---|---|---|---|---|
| 23 (24") | XXS or XS | XXS or XS | between XXS and XS | below S |
| 24 (25") | XS | XS | XS | S |
| 25 (26") | XS or S | XS or S | between XS and S | between S and M |
| 26 (27") | S | S | S | M |
| 27 (28") | S or M | S or M | between S and M | between M and L |
| 28 (29") | M | M | M | L |
| 29 (30.25") | M | M | between M and L | between L and XL |
| 30 (31.5") | L | L | between L and XL | past XL (31") |
| 31 (33") | L or XL | L | XL | past XL |
| 32 (34.5") | XL | XL | between XL and XXL | past XL |
| 33 (36.25") | XXL | XL | past XXL (36") | past XL |
| 14W (37") | XXL | XL | past XXL | past XL |
| 16W (39") | XXL or XXXL | 1X | past XXL | past XL |
| 18W (41") | XXXL | 1X | past XXL | past XL |
Source: Girlfriend Collective sizing guide, Bottoms chart (girlfriend.com/pages/sizing); PopFlex size guide, Imperial table (popflexactive.com/pages/size-chart); Sweaty Betty size guide, Leggings Size Chart (sweatybetty.com/us/size-guide.html); all read Sept. 27, 2026. Bubblelime from the BWWB009 product-page chart as we read it Sept. 13, 2026 (S 25", M 27", L 29", XL 31"); the product page we checked today lists sizes XS–XL without printing the chart in text.
馃憠 The same 29-inch waist is an M at Girlfriend, PopFlex and Sweaty Betty, and an L at Bubblelime. Size labels drift by a full step between brands, which is why the inches matter more than the letter.What if my waist and hip point to different sizes?
It happens on a few rows, because Madewell assumes a 10" hip drop and the legging charts do not all agree:
- Denim 29 (40.25" hip): PopFlex's hip column says L (40"–43") while its waist column says M.
- Denim 30 (41.5" hip): Girlfriend's hip column puts you on the M/L line rather than a clear L.
- Denim 33 (46.25" hip): Girlfriend's hip column says XL (44"–46.5") even though the waist says XXL.
Leggings are knit, so the waistband is the part with the least give once the fabric is stretched across the hips. If you are torn, start from the waist and read how much spandex the pair has; a higher share forgives a snug hip better. The full measuring routine is in how to measure for a leggings size.
Can I use a numeric size like a US 8 instead?
Only if you know whose US 8. Sweaty Betty is one of the few activewear brands that prints numeric sizes next to its letters: US 2 is XXS (23"), 4 is XS (25"), 6 is S (27"), 8 is M (29"), 10 is L (31"), 12 is XL (33") and 14 is XXL (36"). By waist, its US 8 matches a Madewell denim 28.
The UK column is where it breaks. Madewell's conversion tab pairs denim 27 with a UK 8, which is a 28" waist. Sweaty Betty's chart calls a UK 8 an XS with a 25" waist. Same label, three inches apart. We walked through Sweaty Betty's full UK and US ladder in our Sweaty Betty notes.
Why do my jeans fit at a smaller number than the chart says?
Two common reasons. Stretch denim gives, so a jean can close at a smaller number than your tape measure suggests. And brands cut their charts differently; Madewell's own page notes that sizes may vary by manufacturer. If your jeans are a stretch style you sized down in, add one denim size before you use the table above. The same brand can even run two charts at once, which we covered in same brand, different size charts.
Does jeans length tell me my legging inseam?
Not directly. A jean's length is cut to sit at the shoe, while most full-length leggings are meant to end at or just above the ankle bone. Sweaty Betty's full-length legging is a 27" inseam (68 cm), its 7/8 is 24" (60 cm). So compare a legging inseam to your crotch-to-ankle-bone measurement, not to the length on your jeans. Our inseam by height chart covers the rest.
FAQ
Is a size 28 jean a medium in leggings? At Girlfriend Collective, PopFlex and Sweaty Betty, yes, going by the 29" waist on Madewell's chart. At Bubblelime it reads L.
Is a size 26 jean a small? Yes on all three activewear charts above (27" waist). Bubblelime reads M.
What about plus-size jeans? A 16W (39" waist) is XXL or XXXL at Girlfriend and 1X at PopFlex. Girlfriend runs to 6XL (49.5"–53"), which we compared with other brands' top sizes in five brands' size labels.
TL;DR — A denim size is not your waist. On Madewell's chart, 23 to 28 each run one inch bigger than the label, and 29 to 33 run 1.25" to 3.25" bigger. Convert to inches first, then read the legging chart: a 27 jean (28" waist) is S or M at Girlfriend Collective and PopFlex, a 28 (29") is M at both, a 30 (31.5") is L. Brand letters drift a full size, so check the chart every time. More practical walk-throughs are on our guide page, and CRZ Yoga vs. Girlfriend Collective shows two charts on one table.
Sources
- Madewell Denim Size Chart, Measurements and Conversions tabs (madewell.com/Denim-SizeChart.html), read Sept. 27, 2026.
- Girlfriend Collective sizing guide, Bottoms chart and FAQ (girlfriend.com/pages/sizing), read Sept. 27, 2026.
- PopFlex size guide, Imperial table (popflexactive.com/pages/size-chart), read Sept. 27, 2026.
- Sweaty Betty size guide, Leggings Size Chart, Inseam Leggings table and International Conversions (sweatybetty.com/us/size-guide.html), read Sept. 27, 2026.
- Bubblelime BWWB009 product-page size chart, read Sept. 13, 2026; product listing (sizes XS–XL, 25" to 28" inseams) rechecked Sept. 27, 2026.