Most maternity brands size clothing to your pre-pregnancy size, so start there, then confirm with the brand’s chart using your bust, belly, and hip measurements.
Pregnancy changes your body in ways a standard size chart never accounts for, which is why sizing for maternity clothes throws so many shoppers off. The good news: while your belly and bust grow, your bone structure and foot size stay the same, so most maternity lines build their sizes around the number you wore before pregnancy.
How Do Maternity Sizes Compare To Regular Sizes?
Maternity sizes track pre-pregnancy sizes closely, but each retailer sets its own conversion. Kohl’s a:glow maternity chart maps XS to a pre-pregnancy size 2, S to 4/6, M to 8/10, L to 12/14, XL to 16/18, and XXL to 20. Motherhood’s chart follows the same pattern, listing XS as size 2, S as 4–6, M as 8–10, L as 12–14, and XL as 16–18, with corresponding bust, waist, and hip ranges for each.
The catch is that these charts are not universal. One brand’s medium might run looser through the hips, while another cuts narrower through the bust. That’s why the size you wore before pregnancy is a launching point, not a guarantee — always check the maternity-specific chart for the exact item you’re buying.
What Measurements Do You Need For Maternity Sizing?
You need four measurements to size maternity clothes accurately: bust, waist (or bump), hips, and inseam for pants. Take them with a soft tape measure kept level to the floor, not angled or twisted.
- Bust: Measure around the fullest part of your chest, keeping the tape straight across your back.
- Waist: For maternity charts, measure at your natural waist or over the fullest part of your bump, depending on what the specific chart asks for.
- Hips: Measure around the fullest part of your hips and rear.
- Inseam: Run the tape from your inner thigh down to your ankle to find your pants length.
Take these measurements while wearing the kind of undergarments you’d wear with the clothing, and re-measure every few weeks — your bump grows faster than you expect. If you’re between sizes, order up; compression across the belly or bust is uncomfortable and can restrict movement as your body continues to change.
Maternity Size Charts At A Glance
| Maternity Size | Kohl’s a:glow (Pre-Pregnancy) | Motherhood (Pre-Pregnancy) |
|---|---|---|
| XS | 2 | 2 |
| S | 4/6 | 4–6 |
| M | 8/10 | 8–10 |
| L | 12/14 | 12–14 |
| XL | 16/18 | 16–18 |
| XXL | 20 | 20 |
Some charts include international conversions for US, UK, and EU sizes, and others list measurements in centimeters. Double-check the region on the retailer’s page before ordering, especially from international brands, so you don’t accidentally buy a UK 10 thinking it’s a US 10.
Mistakes To Avoid When Sizing Maternity Clothes
The most common error is assuming all maternity brands size identically. Charts vary by retailer and by product type — a maternity dress from one label may fit completely differently than leggings from another. Always verify against the maternity-specific chart, not a standard women’s size chart.
Another frequent mistake: shopping for maternity leggings, dresses, or nursing bras using your old go-to sizes without checking the new chart. These items have different coverage requirements, and the fit logic that worked for your pre-pregnancy wardrobe doesn’t carry over. BabyCenter’s guide to how maternity clothing sizes work emphasizes that if you’re between sizes or shopping for later in pregnancy, choose the roomier option — your body will keep changing, and a fit that leaves growth room will last longer than one that’s snug at purchase.
If you’re looking for looser-fitting options that conceal the bump entirely, our roundup of the best clothes to hide pregnancy covers styles that prioritize coverage and comfort over traditional maternity cuts.
FAQs
Should I Buy Maternity Clothes In A Bigger Size?
Only if you’re between sizes or shopping for the third trimester. Most maternity brands build extra room into the belly and bust, so your pre-pregnancy size usually fits throughout pregnancy. When in doubt, sizing up is safer than buying something that compresses your bump or bust.
Do Maternity Sizes Match The Brand’s Regular Sizes?
Maternity sizes start from the same numerical base as regular sizes, but the cut is entirely different. The bust and belly have more room, and the hips are designed to accommodate a growing bump. Check the maternity-specific chart rather than assuming a regular size 8 translates directly.
How Often Should I Re-Measure During Pregnancy?
Every four to six weeks is a practical rhythm, since your bump, bust, and hips change at different rates each trimester. Re-measure before any big shopping trip, and keep your latest numbers saved in your phone so you can compare them against charts while browsing online.
References & Sources
- Kohl’s. “a:glow Women’s Maternity Clothing Size Chart.” Maps maternity sizes XS–XXL to pre-pregnancy sizes 2–20.
- Motherhood. “Size Guide.” Lists US maternity size conversions with corresponding bust, waist, and hip measurements.
- BabyCenter. “How do maternity clothing sizes work?” Explains that pre-pregnancy size is a starting point and fit varies by brand and product type.