What Is Sizing Like at Oscar de la Renta Clothing?

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

Oscar de la Renta runs small — typically one to two sizes smaller than standard UK sizing — and the brand uses US sizing, so a US 4 is roughly a UK 8, a US 6 is a UK 10, and so on. If you're not already familiar with US-to-UK conversions, that's the first thing to get your head around before you fall in love with a gown online and order the wrong one entirely. I've seen it happen. I've nearly done it myself. Oscar is one of those brands where getting the sizing right is absolutely worth the effort, because when it fits perfectly, it genuinely feels like nothing else.

The House of Oscar de la Renta

Founded in New York in 1965 by the Dominican-born designer Oscar de la Renta, this is one of fashion's most enduringly romantic houses. If Chanel is architecture and Valentino is passion, then Oscar de la Renta is pure, unapologetic femininity — think the most exquisite ruffled gowns, perfectly proportioned cocktail dresses, and that iconic floral aesthetic that has dressed heads of state, First Ladies, and A-listers for over five decades. Since Oscar's passing in 2014, the house has been steered brilliantly by Fernando Garcia and Laura Kim, and the codes of the house remain beautifully intact. This is occasion dressing at its absolute finest.

It's also worth knowing that Oscar de la Renta is predominantly an occasion and ready-to-wear brand — you're buying dresses, gowns, tailored separates, and some accessories rather than a full wardrobe offer. So when you're investing in a piece, the fit is everything.

Oscar de la Renta Size Conversion Table

Oscar de la Renta uses US sizing throughout. Here's your essential conversion guide:

US SizeUK SizeEU SizeIT SizeBust (cm)Waist (cm)Hips (cm)04323679–8160–6285–8726343882–8463–6588–9048364085–8766–6891–93610384288–9169–7294–97812404492–9573–7698–1011014424696–9977–80102–10512164448100–10481–85106–11014184650105–10986–90111–115

Measurements are approximate. Oscar de la Renta's fit is structured and precise — always use the specific garment's measurements where available on the product page, as cut varies considerably between styles.

Fit by Garment Type — What You Actually Need to Know

Oscar de la Renta isn't a brand where one size rule covers everything. The house produces pieces across several distinct silhouettes, and they each carry their own fit quirks:

Ball Gowns & Evening Dresses: These are the pieces the house is most famous for, and they are cut with extraordinary precision. The bodice is almost always structured and boned, which means there is very little stretch or give. Measure your bust and waist carefully and match to the garment's measurements exactly — do not assume your usual size will work. If your measurements fall between sizes, size up. A slightly looser bodice can be taken in; a too-tight one is a whole different problem on the night.
Cocktail & Midi Dresses: A touch more forgiving than the gowns, but still cut close to the body. These dresses typically have that beautiful nipped-waist silhouette that Oscar is known for, so again — measure your waist. If you're bigger across the hips or chest relative to your waist, you may need to factor that in.
Tailored Separates & Blazers: These follow the US sizing pattern faithfully. The tailoring is very precise — slim, elegant, and not designed for a relaxed slouchy fit. Stick to the size guide here and, if in doubt, go up a size rather than down.
Knitwear & Casual Pieces: The (relatively) more relaxed end of the Oscar de la Renta wardrobe. These tend to have a little more ease, though still tailored by most standards. True to US size for most styles.
Bridal: Oscar de la Renta bridal is a separate conversation entirely, as bridal sizing always runs small across the industry. Book a proper appointment with a stockist and prepare to order up two to four sizes from your ready-to-wear size. This is completely standard practice for bridal.

My Stylist's Advice for Buying Oscar de la Renta

I'll be straight with you — Oscar de la Renta is not the most accessible brand to buy online without some careful preparation, and that's not a criticism of the brand, it's just the reality of buying precisely-constructed luxury fashion without a fitting. My honest advice:

Always measure yourself properly before ordering — bust, waist, and hips — and compare to the specific garment measurements, not just the general size chart.
If you're buying from a stockist like Net-a-Porter, MatchesFashion, or Mytheresa, use their live chat or customer service. These teams know the product well and can advise on specific styles.
For occasion wear specifically — a wedding guest outfit, a black-tie event — it is always worth considering whether you can try in person first. Oscar de la Renta is stocked at some UK department stores and luxury boutiques, and the experience of actually trying on one of these dresses is something else entirely.
Check the returns policy before you buy. Luxury e-commerce has generally become very good at this, but always confirm before you commit.

High Street Alternatives for the Oscar de la Renta Aesthetic

Not everyone's wardrobe budget stretches to Oscar de la Renta every time, and that's perfectly fine — the aesthetic can absolutely be captured at a much lower price point if you know where to look. These are my picks for the feminine, occasion-focused Oscar look on the high street:

Hobbs — Consistently excellent for elegant, tailored occasion dressing. Their midi dresses and formal separates have a real sophistication to them, and sizing is generally true to UK.
Phase Eight — Probably the high street's best-kept secret for gorgeous occasion wear, with beautiful embellished and floral styles that genuinely capture that romantic, feminine aesthetic. A go-to for weddings and black-tie events.
Whistles — For the tailored separates and more minimal, elevated aesthetic in Oscar's range. Excellent quality fabrics and consistently elegant cuts.
Anthropologie — Brilliant for the floral, romantic, slightly bohemian side of Oscar de la Renta. Their occasion dresses in particular often feel far more luxurious than the price tag suggests.
Monsoon — A brilliant destination for embellished, feminine occasion dresses at an accessible price. Better than people give it credit for, especially for special events.
Coast — Very strong for formal occasion wear. The bodice-focused structured shapes and embellished options genuinely give a nod to the Oscar de la Renta world without the eye-watering price tag.
Jigsaw — For the more restrained, quietly luxurious end of Oscar's aesthetic. Beautiful fabrics and very considered cuts; sizes true to UK.

Premium & Designer Alternatives

If you love the world of Oscar de la Renta but want to explore at a similar or slightly lower investment level, these are worth knowing:

Reiss — Their occasionwear range has stepped up enormously in recent years. Elegant, well-constructed, and genuinely lovely for formal events. Size true to UK.
LK Bennett — The go-to for polished, feminine British occasion dressing. Their silk and floral dresses in particular are consistently beautiful and hold their own alongside much pricier alternatives.
Claudie Pierlot — The French brand that does effortlessly romantic, feminine dressing with a Parisian lightness of touch. Similar DNA to Oscar but with a more contemporary, accessible sensibility.

Two Independent Picks Worth Discovering

Needle & Thread — A British brand that has become the go-to for embellished, romantic occasion dressing at a price point well below the luxury houses. If you love the floral, feminine, maximally pretty aesthetic of Oscar de la Renta, Needle & Thread is the closest high-quality alternative in the market. Stunning for weddings and black-tie events.
Rixo — A London-founded brand beloved by stylists for its vintage-inspired prints and beautifully feminine silhouettes. The quality is excellent, sizing tends to be true to UK, and the aesthetic genuinely captures that romantic, special-occasion feeling without requiring a second mortgage.

Know Your Exact Size in Oscar de la Renta — Before You Buy

When you're spending serious money on a luxury piece, the last thing you want is a sizing surprise when it arrives. That's precisely what Tellar is for.

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And for more honest, unsponsored style advice, the Tellar Fashion Hub has you covered — a library of free posts written by real stylists, covering every sizing and style question you can think of.

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This post is written by Ella Blake for Tellar Fashion Hub. All brand recommendations are independent and unsponsored. Tellar is free to use and does not accept payment for editorial coverage.