Sisters & Seekers Sizing Guide: What Size Am I?

By Ella Blake — Fashion Stylist | Tellar Fashion Hub — Always honest, unbiased & unsponsored

Sisters & Seekers clothing runs true to size, but with an intentionally oversized silhouette built in — so there's no need to go up a size to get that relaxed, slouchy look the brand is known for. If anything, if you're between sizes and prefer a cleaner fit, sizing down is worth considering. That's the short answer. But if you want to buy with confidence — especially given how fast their drops sell out — keep reading, because the full picture is a little more nuanced.

The Brand in Brief

Sisters & Seekers has built quite the cult following, and honestly, I get it. It's a UK-born, female-founded label that does minimal branding, neutral tones, and that effortlessly cool oversized aesthetic better than most. Their drops move fast, the community around the brand is fierce, and the quality — particularly on their sweatshirts — is genuinely impressive for the price point. Sweatshirts range from around £35–£50, joggers around £40, and t-shirts circa £35. It's not throwaway fashion.

I came across S&S when a client asked me to help her put together a "luxury loungewear" wardrobe without the luxury price tag. I picked up one of their hoodies to test it myself. The fabric is thick, the drop-shoulder sits beautifully, and — crucially — I didn't need to size up to get the slouchy fit I was after. My true size did exactly what it was supposed to do.

How Does Sisters & Seekers Sizing Work?

Here's what you need to know before you order:

Oversized by design: Most hoodies, sweatshirts, and co-ord tops are cut with intentional volume. Don't size up thinking you need to — you'll end up swimming in it.
Joggers run true to size at the waist with a relaxed, wide leg. If your waist sits between sizes, go down.
Fitted pieces (tank tops, crop tees) run true to size or slightly snug — check the fabric content. If there's stretch, you're fine in your usual size. If it's a stiffer cotton, go up if in doubt.
Drop-shoulder styles can look long on petite frames — check body length measurements if you're under 5'4".
The sizing range goes from 2XS (UK 4–6) to 3XL (UK 20–22), which is a genuinely inclusive range for the brand.

Sisters & Seekers Size Guide: UK Sizing Chart

Bust measurements:

SizeUK SizeBust (inches)Bust (cm)2XS4–628–30"71–76 cmXS6–830–32"76–81 cmS8–1032–34"81–86 cmM10–1234–36"86–91 cmL12–1436–38"91–96 cmXL16–1838–40"96–101 cm2XL18–2040–42"101–106 cm

Waist measurements:

SizeUK SizeWaist (cm)2XS4–659–62 cmXS6–862–65 cmS8–1065–70 cmM10–1270–75 cmL12–1475–80 cmXL16–1885–90 cm2XL18–2090–97 cm

Hip measurements:

SizeUK SizeHips (inches)2XS4–634–35"XS6–835–37"S8–1037–39"M10–1239–41"L12–1441–43"XL16–1843–44"2XL18–2044–46"

Garment-by-Garment Breakdown

Hoodies & Sweatshirts: Stick to your true size, full stop. These are intentionally cut oversized, with wide shoulders and dropped sleeves. I ordered a Medium (I'm a UK 10–12) and it sat perfectly — slouchy without looking like I'd borrowed it from someone twice my size. If you're petite, be mindful of body length.

Joggers & Sweatpants: True to size at the waist. The leg is wide and relaxed. They do wash and wear beautifully, and the co-ord sets are genuinely worth the investment — the fabric weight matches across pieces, which not all brands bother with.

T-shirts & Crop Tops: These depend on the cut. Boxy, structured tees can be sized down for a neater look. Softer jersey styles are more forgiving — your true size will work fine. If you're buying to wear tucked or knotted, your usual size is great.

Knitwear: This is where I'd be a touch more cautious. Knit hoodies in particular can vary in drape depending on the yarn weight. Check the product description for whether it's a relaxed or fitted knit — S&S usually notes this clearly.

If You're Between Sizes

Go down. The oversized construction means even sizing down will still give you a relaxed, intentional look. Going up risks tipping into shapeless rather than stylish — and trust me, there is a difference, even if it's subtle.

Similar Brands to Consider

If Sisters & Seekers isn't quite right for you — whether it's sizing, budget, or availability — here are some brilliant alternatives across every price point:

High Street Picks:

ASOS — A huge range of co-ord loungewear sets, often in the same neutral, minimal aesthetic. Sizing is generally true to size on their own-brand pieces.
Urban Outfitters — Great for oversized branded sweatshirts with a similar drop-shoulder aesthetic. Size up if you want the full slouch here.
Hollister — Underrated for soft, heavyweight fleece. Their co-ords are excellent quality for the price and wash incredibly well.
Abercrombie & Fitch — Their YPB (Your Personal Best) activewear line and everyday sweats have had a serious glow-up. Brilliant quality, consistent sizing.
All Saints — For the slightly more elevated everyday piece. Their jerseys and oversized knits have the same understated cool without the branded logo.
Sweaty Betty — If you want the comfort of loungewear with more structured performance fabric, Sweaty Betty delivers. Sizing runs true.
Hush — Brilliant for women who want that same clean, neutral palette but slightly more grown-up. Incredibly soft fabrics and consistent sizing across the range.

Two Independent Picks:

Colorful Standard — A Danish brand doing sustainable, beautifully pigmented basics. The sweatshirts and tees are exceptional quality and the colour palette is genuinely gorgeous. Sizing runs slightly slim — go up one.
Pangaia — If you love the S&S ethos but want premium materials and sustainability credentials to match, Pangaia is the answer. Their FLWRDWN and recycled cotton pieces are stunning. True to size.

Premium & Luxury:

Totême — For when you want the oversized minimalist look but in truly investment-grade fabric. Their off-duty jersey pieces are deeply chic.
The Row — The gold standard in quiet luxury loungewear. Eye-watering price, extraordinary quality.

Never Guess Your Size Again — Try Tellar Free

Getting your Sisters & Seekers size right — especially on a limited drop — is the difference between a wardrobe win and a return. That's exactly why I always recommend Tellar.co.uk, the UK's leading free sizing tool.

Measure once using your bust, waist, hips, or an existing brand size you trust
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It also has a brilliant Fashion Hub packed with honest, unsponsored style advice from our stylists — no paywall, no agenda. Just good guidance.

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