How to Find Your Size in Oversized Jeans (Without Looking Like You've Borrowed Your Dad's)

By Ella Blake, Tellar Stylist

Finding your size in oversized jeans is not about going up a size or two in your usual style — it's about understanding a completely different fit logic and knowing your waist and hip measurements before you start. Get it right, and oversized jeans are genuinely one of the most flattering, effortless things you can wear. Get it wrong, and you'll spend the day yanking them up and looking like you've raided someone else's wardrobe by mistake.

I'll be honest — I got it wrong for an embarrassingly long time. My first attempt at the oversized trend involved ordering my regular slim-fit jean size in a baggy style from a brand I'd never tried before. They arrived, I put them on, and my flatmate said, with no malice whatsoever, "are those your boyfriend's?" They were not the look I was going for. The problem wasn't the style — it was that I hadn't understood what "oversized" actually means in denim terms, and I hadn't checked my measurements against the brand's guide. Lesson very much learned.

Why Oversized Jeans Fit Differently to Everything Else

Standard jeans are designed to follow the contours of your body fairly closely. Oversized jeans are intentionally cut with extra room through the seat, thigh, and leg — but they still need to sit properly at the waist (or hip, depending on the rise) to actually work as an outfit. That's the key distinction. The "oversized" refers to volume through the body of the jean, not necessarily at the waistband.

This means that sizing up randomly often results in a waistband that gaps, bunches, and folds over, which doesn't look intentionally relaxed — it just looks ill-fitting. The goal is a waist that sits securely while the rest of the jean has that lovely, deliberate bagginess through the leg.

The Measurements You Need Before You Shop

Two numbers will solve almost every oversized jeans dilemma:

Waist: Measure around your natural waist — the narrowest point of your torso, a couple of inches above your belly button. Don't cheat. This number anchors the whole jean.
Hips: Measure around the fullest part of your bottom and hips. For low or mid-rise oversized styles, this is actually your most critical measurement, because the jean sits here rather than at your waist.
Inside leg: If you're buying online, this matters more than people think. Oversized jeans often come in one standard length, and the way they break at the ankle is part of the whole look. Measure from your crotch to the floor barefoot.

Take these to every brand's size chart — and actually use the centimetre or inch columns rather than defaulting to your usual trouser size. Sizing varies so wildly across denim brands that your number genuinely means very little without the measurements to back it up.

How to Size Oversized Jeans by Rise

The rise of the jean changes which measurement you prioritise:

High-rise oversized jeans: Size for your waist. The waistband sits at or above your natural waist, so that measurement rules. If you're between sizes, go up — a slightly roomy waistband can be held with a belt and looks intentional; one that won't fasten is a problem.
Mid-rise oversized jeans: Balance both measurements. The waistband hits between hip and natural waist, so both numbers matter. Check the brand's size chart for both and see which size accommodates you best.
Low-rise baggy jeans: Go entirely by hip measurement. The waistband sits on the hip, and if it doesn't clear your fullest point, nothing else matters.

What the High Street Gets Right (and Wrong)

Here's my honest guide to how some of the best-known brands handle oversized denim — because they are not all equal:

Levi's — Their Baggy Dad and '94 Baggy styles are benchmarks for the oversized jean trend. Levi's sizing is in inches (waist x length), which is actually more accurate than UK sizing for jeans. Measure your waist in inches and use that number directly — it's reliable. They tend to run true to the listed waist measurement.
ASOS — Huge range of oversized and baggy styles across multiple price points. Sizing can be inconsistent between their own-brand and third-party labels, so always check individual size guides rather than assuming your ASOS size carries across. Their tall and petite ranges are genuinely worth exploring for length.
Abercrombie & Fitch — Their '90s Relaxed and Curve Love ranges have become cult favourites. Abercrombie are unusually good at designing for different hip-to-waist ratios, and their size guide is one of the most detailed on the high street. Highly recommended for shopping online — their returns are also excellent.
Zara — European sizing, so slightly narrower through the hip than UK equivalents. If you're between sizes, go up. Their TRF baggy styles are very on-trend but can be cut slim through the thigh despite the "oversized" label — always check the product description carefully.
Topshop (via ASOS) — The Topshop Mom and Kort styles have long been reliable favourites. Sizing tends to run slightly generous, which is actually great for the oversized look. Their petite range is one of the better ones available.
Mango — Their wide-leg and boyfriend styles are really well cut, but like Zara they use European sizing. Size up if you're on the cusp. The quality at the price point is very good and they photograph well on the site, which makes online shopping easier.
Citizens of Humanity — Premium denim, and worth every penny for the fit. Their Horseshoe and Gaucho styles are oversized done brilliantly. Sizing is in US inches but very accurate — measure your waist in inches and trust the chart. They're particularly good for women with a smaller waist and fuller hips.
Paige — Another premium denim brand with exceptional quality and fit. Their Mayslie and Carly styles offer that relaxed, wide-leg look without swamping you. Their size guide is thorough and their customer service will help you find the right fit if you call.
Boden — Underrated for denim. Their relaxed-fit styles are well-proportioned and their sizing is very consistent — a brand you can genuinely trust for online shopping without the usual guesswork.

Two Independent Brands That Do Oversized Denim Brilliantly

Agolde — A Los Angeles-based denim label that has quietly become one of the most respected names in relaxed and oversized jeans. Their '90s Pinch Waist and Cargo styles are stocked in the UK through Net-a-Porter and a handful of independents. The sizing is in US measurements and runs true — their size guide is excellent and the fit is worth the investment. This is what proper denim craftsmanship looks like.
Waven — A brilliant UK-based sustainable denim brand that doesn't get nearly enough attention. They make considered, well-fitted relaxed jeans with inclusive sizing and a genuinely transparent approach to production. Their Asa Wide Leg and oversized styles are a cut above the high street and the price point is very reasonable. One to bookmark.

Styling Tips to Make Oversized Jeans Look Intentional

Getting the size right is half the battle — styling them properly is the other half:

Tuck or half-tuck a fitted top or shirt to create waist definition. The contrast between a nipped-in top and relaxed jeans is the whole point of the look.
Avoid volume on both top and bottom simultaneously — oversized jeans work best with something fitted or cropped on top, not another roomy layer.
The break at the ankle matters. A slight scrunch or stack looks deliberate; pooling fabric on the floor looks like you bought the wrong size. Get the length right or get them hemmed.
A belt at the waist — even a simple leather one — immediately elevates the look and stops a slightly generous waistband from looking sloppy.

Find Your Exact Size Across 1,500+ Brands — Free

Denim sizing is one of the most confusing areas of fashion — and oversized styles add another layer of complexity on top. This is exactly what Tellar.co.uk is built for. It's the UK's leading free sizing tool, matching your exact measurements to the right size across 1,500+ brands instantly. No more size chart squinting. No more returns pile.

Measure once — enter your waist, hip, and inside leg (or a brand size you know fits well).
Use the Store Size Lookup tool to get your precise size in any brand — Levi's, ASOS, Abercrombie, Citizens of Humanity, and hundreds more.
Always free — no downloads, no sign-up, no strings. Works instantly in your browser.

The Tellar Fashion Hub is also packed with free, honest style guides from real stylists — no ads, no brand deals, no fluff. Just genuinely useful fashion advice whenever you need it.