How Do I Find My Size in Boyfriend Jeans?

TELLAR FASHION HUB — JEANS & FIT GUIDES

By Ella Blake, Tellar Stylist

Boyfriend jeans fit differently to almost every other cut in your wardrobe — and that's precisely what makes sizing them such a headache. The short answer: size down by one, measure your waist and hips, and always check the specific brand's inseam because the "relaxed" fit varies wildly from label to label. But there's quite a bit more to it than that, so let me walk you through exactly what to look for.

Why Boyfriend Jeans Are Their Own Sizing Beast

I'll be honest — my first pair of boyfriend jeans were a total disaster. I bought them in my usual size, convinced the bagginess was the whole point. I looked like I'd borrowed my dad's jeans on laundry day. Not intentionally cool. Just... wrong. The problem is that boyfriend jeans are supposed to look intentionally oversized, but there's a very fine line between "effortlessly slouchy" and "I've lost my actual body in here."

The relaxed fit is cut with extra room through the seat, thighs, and — crucially — the waist. That means the waistband often gaps at the back unless you size correctly. Unlike skinny jeans, where stretch fabric forgives a multitude of sins, boyfriend jeans are typically stiffer cotton or denim, so what you buy is what you get.

The Golden Rules for Getting Your Size Right

Size down one from your usual jeans size — the relaxed cut already builds in extra room; sizing up makes them look unkempt rather than casual
Prioritise your waist measurement — gaping at the back is the number one fit complaint with boyfriend jeans; a snug waistband anchors the whole look
Check the inseam length carefully — boyfriend jeans are typically cut to sit at ankle or just-below-the-knee, and the "right" length changes the entire silhouette
Account for the rise — mid-rise and high-rise boyfriend jeans fit very differently; high-rise tends to be more forgiving if you carry weight around your middle
Try sitting down in the fitting room — comfort through the thighs matters because the cut shouldn't be so baggy that the crotch drops to your knees when seated

How to Measure Yourself for Boyfriend Jeans

Grab a soft measuring tape. You want three numbers:

Waist: Measure around the narrowest part of your torso — not where you wear your jeans, but your natural waist (usually an inch or two above your belly button)
Hips: Measure around the fullest part of your hips and seat, roughly 7–9 inches below your natural waist
Inside leg: From your crotch to the floor — this tells you which inseam length to select (most brands offer 28", 30", or 32" for women's cuts)

Now here's the slightly irritating truth: a size 28 waist in Levi's is not the same as a size 28 in ASOS or Mango. Vanity sizing means numbers are essentially meaningless without checking the brand's actual centimetre measurements. More on that below.

Brand-by-Brand: What to Expect

Because I've tried an embarrassing number of boyfriend jeans over the years (occupational hazard, honestly), here's my honest take on how some of the best-loved labels size up:

Levi's — The 501 and 94 Baggy are the gold standard. Levi's runs true to size but slightly narrow through the hips; size up if you're curvy. Their waist-to-hip ratio doesn't suit everyone straight off the rack — a tailor can work magic on the waist if needed.
ASOS — Great for petites and talls as they offer multiple length options. Sizing is consistent but their denim is on the softer side, so it can stretch through the day.
Mango — Their boyfriend jeans are cut with a slightly higher rise than average, which is great for avoiding the gap-back problem. Size down confidently here.
Zara — Notoriously inconsistent sizing season to season. Always try before you buy, or use the brand's cm measurements rather than the number on the label.
Cos — Minimalist and well-cut; they tend to run true to size and the denim is sturdy. Their drop-crotch style is particularly good on slender frames.
Whistles — A brilliant mid-market option if you're between a high-street and premium budget. Their boyfriend styles are tailored and flattering; true to size.
Abercrombie & Fitch — Genuinely excellent boyfriend and '90s fit jeans right now. They size inclusively and offer a wide range of washes. Size down one.
Citizens of Humanity — Premium denim done brilliantly. Their Emerson and Daphne styles are among the best boyfriend cuts on the market. Size down; the denim has minimal stretch.
Paige — Luxury denim with a flattering cut; slightly more give than CoH. The Jimmy boyfriend is a fan favourite and suits most body shapes.
Reiss — More elevated and tailored than most; great if you want boyfriend jeans that work in a smart-casual work setting.
Urban Outfitters — Trend-led and great value; sizing runs small so go up a size here. Good for achieving that truly baggy, skater-girl look.

Two Independent Brands Worth Knowing

I always love shining a light on smaller brands doing brilliant things with denim:

Boyish Jeans — A sustainably made denim brand (based in LA but widely shipped to the UK) with some of the best boyfriend cuts I've come across. Their sizing chart is genuinely accurate and they cater to a wide size range.
Nudie Jeans — Swedish brand with a cult following. Their organic denim boyfriend styles (the Lazy Leo in particular) are beautifully made, size consistently, and actually get better with age and washing.

Styling Tips Once You've Found Your Size

Once you've nailed the fit, the good news is that boyfriend jeans are extraordinarily versatile. A few rules I live by:

Roll the hem slightly — even one small cuff changes the whole silhouette, making the ankle visible and elongating the leg
Tuck in your top — a front-tuck (even just one half of the hem) prevents the outfit reading as shapeless
Balance the volume — a relaxed leg needs something fitted or structured on top; an oversized jumper with boyfriend jeans only works if you're going for a deliberately casual, street-style look
Shoe choice is everything — a pointed-toe flat or low heel elongates the leg; chunky trainers lean into the relaxed vibe; avoid ankle boots with a wide shaft as they compete with the cuff
A belt makes a difference — especially if you've sized down for the hips but the waist is slightly loose; a thin belt threaded through the loops polishes the look

What About Body Shape?

Boyfriend jeans genuinely suit most body shapes — but the fit details matter:

Pear shapes — look for a high-rise cut to balance proportions; avoid low-rise which can emphasise the hips
Apple shapes — a mid-to-high rise with a slightly tapered leg (not fully straight) is most flattering; avoid drop-crotch styles
Hourglass shapes — you may need to size up for the hips and take them in at the waist, or look for stretch denim that accommodates the difference
Petite frames — stick to a cropped inseam (28" or under) and avoid any extra volume at the hem; roll the cuff just once
Tall frames — lucky you, almost all boyfriend styles work well; lean into the full-length inseam for a modern look rather than cropping

Never Guess Your Jeans Size Again — Use Tellar

Sizing varies so much between brands that even experienced stylists find it maddening. That's exactly why Tellar.co.uk exists — it's the UK's leading free sizing tool, matching your exact measurements to over 1,500 brands instantly. No more guesswork, no more returns.

Here's how it works:

Measure once — using your bust, waist, hips, or an existing brand size you already know fits
Use the Store Size Lookup tool to get your precise size in any brand — whether that's Levi's, COS, Citizens of Humanity, ASOS, or somewhere more niche
Always free — no app download, no subscription, works straight in your browser

And while you're there, the Tellar Fashion Hub is packed with free, unbiased style posts from our stylists — covering everything from fabric guides to body shape advice. Honest. Independent. Always free.

For more help with jeans sizing and fit, don't miss these reads:

The bottom line? Boyfriend jeans reward the effort you put into finding the right fit. Once you've got a pair that hits properly at the waist, sits comfortably through the thigh, and lands at the right point on your ankle — you'll wear them constantly. Trust me, I speak from hard-won experience.