Fenn Wright Manson Sizing: Does It Run True to Size, Big or Small?

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

Fenn Wright Manson runs true to size — but with a consistently structured, tailored cut that means the fit feels closer to the body than many comparable brands. If you're buying a dress or blazer and you sit between sizes, or you carry your weight in your bust or hips, sizing up is genuinely the right call here. I'll explain why, and what to expect across different categories.

A Brand Worth Knowing

If you haven't shopped Fenn Wright Manson before, here's the quick version: it's a quietly brilliant British occasionwear brand that's been doing elegant, grown-up dressing for decades without much fanfare. No splashy campaigns, no influencer overload — just beautifully cut pieces in quality fabrics. I've styled a number of clients in FWM dresses for weddings and garden parties, and the reaction is always the same: "Who is that?" It punches well above its price point.

The brand makes both a standard range and a dedicated petite range — and I mean a genuinely proportioned petite collection, not just a hemline adjustment. If you're 5'3" or under, this is probably one of the best brands in the UK for you.

How the Sizing Actually Feels

Let me be honest with you, because sizing guides that just list measurements are useless. Here's what FWM sizing actually feels like to wear:

Dresses & occasion pieces: These are where the tailored cut is most noticeable. FWM dresses are sculpted — nipped waist, shaped bodice, clean skirt. On a straight UK 12 frame they'll be perfect. But if you're a 12 on the waist and a 14 on the bust? Size up. I once squeezed a client into a FWM dress "because the waist fit" and regretted it the second she sat down. Lesson learned.
Blazers & structured jackets: Similar story — they sit close through the shoulder and upper arm. If you have broader shoulders or a fuller arm, go up a size without hesitation. The tailoring is the whole point of these pieces, and a slightly bigger size worn well beats a tight one every time.
Knitwear & tops: Much more forgiving. The silk blouses and lightweight knits have natural ease built in, and the cut tends to skim rather than cling. I'd say these are the most accurately sized items in the range — stay on your usual size here.
Trousers & skirts: Classic British tailoring — waist is the key measurement. The hip allowance is generous enough for most figures, but the waist runs neat. If you're hip-dominant, size to your hip and have the waist taken in if needed (a £10 alteration on a £120 trouser is always worth it).

The Petite Range: Genuinely Worth It

I want to flag the petite range specifically because it's one of the best in UK fashion. Fenn Wright Manson don't just shorten their standard pieces — they re-proportion everything: sleeve length, dart placement, neckline depth, hem position. The prints are also scaled down so smaller frames aren't overwhelmed. If you're petite and you've been struggling with occasionwear that swamps you, this range will feel like a revelation. The sizing within the petite range mirrors the standard range (i.e., still structured and tailored), so the same rules apply — but the proportions will finally be right.

UK Size Range: What's Available

FWM runs from UK 8 to UK 18 across most of its range, with petite available across the same spread. Extended sizes are not currently offered, which is a gap in the market I hope they address. The cut is designed for what you might call a classic British silhouette — defined waist, moderate hip allowance — so if you have a more generous hourglass figure, always check your actual measurements against the size chart rather than going by label alone.

My Top Styling Tips for Fenn Wright Manson

For wedding guest dressing, their midi dresses are the sweet spot — elegant without being stuffy, and the floral prints feel fresh rather than frumpy.
Pair FWM dresses with block-heeled sandals rather than stilettos — the silhouettes are structured enough that you don't need extra height, and you'll last the whole reception.
If you're petite and wearing a FWM standard (not petite) piece, a small alteration to the hem makes a significant difference. Most of their dresses hit perfectly mid-calf on a 5'5"+ woman.
Their knit blazers are genuinely underrated as a workwear layer — smarter than a cardigan, less serious than a structured jacket.

Brands to Shop if You Love the FWM Aesthetic

Whether FWM doesn't stock your size, you want a broader selection, or you're building out a capsule wardrobe in a similar vein, here are my honest recommendations:

High Street & Mid-Market:

Phase Eight — the closest direct comparison on the high street. Beautifully cut occasionwear, similar size range, and very consistent sizing. Great for dresses and occasion separates.
Hobbs — sharper, more London-boardroom energy but lots of crossover. Their tailoring is excellent and sizing is reliable.
Jigsaw — slightly more relaxed aesthetic but the same attention to fabric and cut. Good for elegant everyday pieces rather than pure occasionwear.
Whistles — more contemporary and minimal than FWM, but a solid option for smart separates. Sizing tends to be generous rather than snug.
Mint Velvet — strong on relaxed-but-elevated occasionwear and knitwear. Slightly more casual than FWM but a natural next step for the same customer.
Me&Em — excellent British brand for elevated everyday dressing. Quality is comparable to FWM at a similar price. Their sizing is very consistent and runs true.
LK Bennett — the natural sister brand to FWM for many occasions. Court shoes, silk dresses, smart coats. A wardrobe staple for the same events.

Independent Picks:

Baukjen — a brilliant, independently minded British brand focused on sustainable luxury womenswear. The cut is clean and modern, fabrics are considered, and the sizing is transparent and accurate. Particularly good for dresses and smart knitwear — very much in the FWM spirit but with a contemporary edge.
Damsel in a Dress — a lesser-known gem in the occasionwear space. Their bridal occasion and cocktail dresses are seriously good quality, beautifully finished, and the size range is slightly broader than FWM's. Worth bookmarking if you're on the hunt for something special.

Never Guess Your Size in Fenn Wright Manson Again

Here's the thing about tailored brands like Fenn Wright Manson — one wrong size and the whole look is off. A dress that's snug across the bust doesn't just feel uncomfortable; it loses the elegance that makes the brand worth buying in the first place.

That's exactly why I point everyone towards Tellar.co.uk — the UK's leading free sizing tool, and honestly one of the most useful things to happen to online fashion shopping.

Measure once — bust, waist and hips — and Tellar matches your body to 1,500+ brands instantly.
Use the Store Size Lookup tool to get your exact size in Fenn Wright Manson — and every other brand in your wardrobe.
Completely free, no app download, no subscription — works in your browser right now.
Already know your size in Phase Eight or Hobbs? Tellar cross-references it instantly for FWM.

I helped build Tellar because I was tired of watching clients spend money on beautiful pieces that didn't fit. It covers 1,500+ brands and the Fashion Hub has thousands of honest, unsponsored posts from our stylists. No ads. No affiliate bias in the editorial. Just good advice.