As someone who has handled and tested dozens of activewear brands for international buyers, I can confirm that Sweaty Betty does run slightly small, especially compared to US brands like Lululemon or Athleta.
If you’re shopping online or sourcing yoga apparel for your brand, knowing how Sweaty Betty sizing works will help you choose the right fit — or learn from their pattern standards for your own line.
Yes — Sweaty Betty tends to run small, especially in leggings and compression tops.
It follows UK/European sizing standards, which are generally narrower in the hips and shorter in the inseam compared to North American fits.
Most shoppers who are between sizes should go one size up for maximum comfort.
From my experience fitting samples in both UK and US markets, Sweaty Betty sizing sits between Alo Yoga’s snug fit and Lululemon’s flexible stretch.
| Brand | Fit Type | Size Tendency | Key Fit Note |
|---|---|---|---|
| Sweaty Betty | Slim & compressive | Runs small | Designed for a sculpted look |
| Lululemon | True to size | Neutral | Adapts to most body types |
| Alo Yoga | Tight fit | Slightly small | Fashion-forward cuts |
| Athleta | Relaxed | True / slightly big | Inclusive sizing options |
If you wear US 6 in Lululemon, you may need a UK 10 (US 8) in Sweaty Betty.
There’s a design logic behind this fit difference — it’s not a flaw.
Sweaty Betty’s British tailoring roots favor:
That’s why the brand feels more fitted and lifted, but less forgiving for curvier body types compared to US brands.
| Body Type | Recommended Size Move | Notes |
|---|---|---|
| Petite / Slim build | True to size | Provides a supportive, snug feel |
| Curvy / Athletic build | Size up once | More comfort around hips and thighs |
| Tall body frame | Size up for length | Prevent leggings from riding up |
| Between sizes | Go larger | Keeps waistbands comfortable during movement |
Sweaty Betty’s Power and Zero Gravity collections are known for strong compression — so if you like stretch, those may feel tighter than expected.
| Measurement | Sweaty Betty (UK) | Lululemon (US) |
|---|---|---|
| XXS | UK 6 | US 0–2 |
| XS | UK 8 | US 4 |
| S | UK 10 | US 6 |
| M | UK 12 | US 8 |
| L | UK 14 | US 10 |
| XL | UK 16 | US 12 |
👉 Tip: Always check the specific collection — Power leggings fit smaller, while Chill or Super Soft lines fit closer to true size.
Personally, I find UK sizing precision great for performance wear, but for comfort yoga sessions or lounging, going up one size gives more freedom to move.
Q1: Does Sweaty Betty run small or true to size?
Generally small. It’s designed for a snug, performance fit.
Q2: Should I size up in Sweaty Betty leggings?
Yes, especially for compressive styles or if you’re between two sizes.
Q3: Is Sweaty Betty UK or US sizing?
It’s UK-based, so sizes are smaller than standard US equivalents.
Q4: Are Sweaty Betty leggings stretchy?
Yes, but the stretch is firm and sculpting, not overly flexible like Lululemon’s Nulu.
At FuKi Yoga, we specialize in helping yoga and activewear brands achieve the ideal fit for every market — whether you want UK compression or US comfort.
Our services include:
By combining technical precision with fashion-forward design, FuKi Yoga helps brands create better-fitting, high-performance yoga wear trusted by customers worldwide.