US to UK Maternity Size Conversion
| US | UK |
|---|---|
| XS | 6 |
| S | 8 |
| M | 10-12 |
| L | 14-16 |
| XL | 18-20 |
Sizing conventions vary by brand and by cut — this table shows the standard published conversion. Always check the garment's own size chart when one is available. See how these tables are compiled.
US and UK maternity sizing both follow the wearer's pre-pregnancy dress size rather than a separate maternity-specific scale, so a US 8 maternity item converts to a UK 10 — the same offset as regular US-to-UK dress sizing.
Because maternity garments are cut with built-in growing room over the bump, sizing to your regular pre-pregnancy size (converted with this same chart) is the standard advice rather than sizing up further, unless a specific brand's notes say otherwise.
Frequently asked questions
Should I size up for maternity clothing beyond my regular converted size?
Usually not — maternity garments already build in room for the bump at your regular pre-pregnancy size, so the standard dress-size conversion is the typical starting point rather than a further size increase.