Sizing at Omnes? A Stylist's Honest & Unbiased Verdict

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

Omnes sizing generally runs true to size, with a relaxed, slightly generous cut across most of their dresses, blouses, and occasionwear — making it a genuinely inclusive brand that tends to flatter a wide range of body shapes. If you're between sizes, sizing down is usually the safe call. But, as with any brand, there are a few garment-specific quirks worth knowing before you click “add to basket.”

I've been recommending Omnes to clients for a couple of years now — it was one of those brands I stumbled across while hunting for a sustainable occasionwear option for a client who kept getting lost in Zara's sizing inconsistencies. First order in, and we were genuinely impressed. Great fabrics, thoughtful construction, and a size range that actually means something. Let me break it all down for you.

Who Is Omnes?

For the uninitiated: Omnes is a British sustainable fashion brand that launched in 2021, focused on dresses, occasionwear, and elevated everyday pieces made from eco-conscious fabrics — think deadstock materials, TENCEL™, and recycled fibres. They sit at a mid-to-accessible price point (most dresses fall between £60–£120), and they've built a really loyal following for their feminine silhouettes and commitment to sizing inclusivity, running from a UK 4 right up to a UK 26/28 on many styles.

In an overcrowded occasionwear market, that range actually matters — and their fits back it up.

How Does Omnes Sizing Run? The Honest Breakdown

Across the board, Omnes fits true to size — but the cut is what sets them apart. They build in real ease, so there's none of that "technically fits but I can't breathe" problem you sometimes get with bodycon-leaning brands.

• Dresses: Generally true to size. The bodice is usually the snuggest point — if you're fuller in the bust, consider sizing up one and taking in the waist if needed. The midi and maxi lengths are beautifully cut and surprisingly forgiving.

• Blouses & tops: I'd say slightly generous here. If you're a petite size 10 or 12, you might find the shoulder seams drop slightly — worth checking reviews for the specific style.

• Occasionwear & wrap styles: These are Omnes's sweet spot. The wrap cuts are genuinely adjustable and work brilliantly across sizes. True to size with room to breathe.

• Jumpsuits: This is the trickiest category — if you're taller or have a longer torso, be mindful of the rise. I'd always check the measurements on the product page for these.

• Knitwear: Slightly oversized by design on most styles — size down if you prefer a more fitted look.

Omnes Extended Sizing — Does It Actually Work?

Yes — and I say this with genuine enthusiasm because so many brands make a song and dance about “extended sizing” and then just scale up a size 10 pattern without rethinking the proportions. Omnes seems to have put actual thought into their larger sizes. The seaming, the fabric choice, the silhouettes — they hold up. I've had several clients in sizes 18–24 who've raved about the fit. That's not nothing.

What Omnes Gets Right (And Where to Watch Out)

Gets right:

• Consistent sizing across most categories — once you know your Omnes size, you can generally rely on it

• Excellent use of stretch-woven and fluid fabrics that accommodate shape rather than fighting it

• On-site size guides are actually helpful — they include garment measurements, not just body measurements

• The photos use a range of model sizes, which genuinely helps you visualise the fit

Watch out for:

• Structured bodices on some occasionwear styles can feel restrictive in the bust — always check garment measurements if you're a D cup or above

• A few styles are listed as "one size" — approach with caution, as they tend to work best for sizes 10–16

• Petite shoppers may find some maxi lengths are genuinely very long — worth noting if you're under 5'4"

My Stylist Tip for Getting Your Best Omnes Fit

Always measure your bust first — Omnes tends to cut their bodices with a defined structure, so if you're between sizes, go with the bust measurement and adjust elsewhere. I also always check the customer photos on their site (they've got a good community of reviewers) — real women in real sizes are worth more than any size guide.

And if you want to skip the guesswork entirely? Use Tellar's Store Size Lookup — enter your measurements once and get your exact Omnes size instantly. Genuinely saves so much faff.

If You Love Omnes — Try These Too

One of the questions I get asked most is: "What do I shop when Omnes is sold out?" Great problem to have, honestly. Here's where I'd point you, depending on your budget:

High street picks:

• Mango — consistently brilliant for occasionwear and fluid dresses at a similar price point; tends to true-to-size with a slightly more tailored cut than Omnes

• Cos — if you love Omnes's minimalist sustainability angle, COS is your natural next stop; sizing is consistent and their extended range has improved significantly

• Whistles — grown-up occasionwear done properly; sizing is true to size and their dresses hold their shape beautifully

• Phase Eight — a brilliant go-to for occasion dresses especially if you want more structured silhouettes; sizes run true with a flattering fit

• Hobbs — understated British elegance; sizing is reliable and their occasionwear translates brilliantly from event to event

• Me&Em — premium quality at a high-street price point; sizing is consistent and the fabrics are a cut above most of the high street

• Reiss — if you want that elevated feel, Reiss's occasionwear fits beautifully and holds up event after event; true to size with a more fitted silhouette than Omnes

Premium picks:

• LK Bennett — the gold standard of British occasionwear; sizing is extremely consistent, and they've quietly improved their extended sizing too

• Ghost — a wonderful sustainable mid-market option with a very similar aesthetic to Omnes; silky satin-style fabrics and relaxed, true-to-size fits

Luxury picks:

• Rixo — the luxury version of Omnes's occasionwear vibe; vintage-inspired prints, beautiful fabrics, sizes run true but always check the bodice measurements

• Reformation — if sustainability is non-negotiable, Reformation is the premium benchmark; sizing can run slightly small so size up if in doubt

Two independent brands worth knowing:

• Birdsong — a London-based ethical brand with a similar sustainable ethos to Omnes; inclusive sizing, beautifully made, and genuinely different from anything on the high street

• Mia Fratino — an Australian label now shipping to the UK; extraordinary knitwear in premium natural fibres with a luxuriously relaxed fit that Omnes fans tend to love

For more sizing comparisons across these brands, check out The Ultimate Clothing Sizing Guide over on the Tellar Fashion Hub — it covers everything.

And if dresses are your thing (and at Omnes, they usually are), don't miss the Ultimate Guide to Dresses & Best Buys — I've rounded up the best styles by body shape, occasion, and budget.

Never Guess Your Size Again — Tellar.co.uk

Tellar is the UK's leading clothing sizing tool — matching your exact measurements to 1,500+ brands instantly. No more size guides. No more returns. No more guessing.

• Measure once (bust, waist, hips — or use an existing brand size)

• Use the Store Size Lookup to get your precise size at Omnes, COS, Reiss, Arket, & 1,500+ more

• Always free — no app, no download, works in-browser

Plus — the Tellar Fashion Hub is a growing library of free posts from top stylists. Honest. Unbiased. Independent. Always free.

Find Your Size at Tellar →

Wondering what jeans to wear with your Omnes pieces? Have a read of the Best Jean Trends for 2026 — always a good place to start. And if you're building a capsule wardrobe around key outerwear, the Ultimate Guide to Jackets & Best Buys is well worth a browse too.

Bottom line on Omnes? It's one of the more dependable brands I recommend when clients want beautiful, conscious occasionwear that actually fits. True to size, thoughtfully made, and genuinely inclusive. Go with your usual size, check the garment measurements on structured styles, and use Tellar to nail it first time.