Tellar
Search
HomeStore size lookup - WomenStore size lookup - MenFashion HubMeasure Yourself - WomenMeasure Yourself - MenFAQ'sTell me moreCustomer FeedbackContact us

Rat & Boa Sizing Guide: How to Find Your Perfect Fit and What’s Worth Buying

Author: Stylist and brand team at Tellar

Date: 2025

Honest. Unbiased. Independent. Free. We promise.

We will never be influenced by brands - just the perfect Fit, Size & Style for you. Search thousands of honest posts for free, written by our stylists - your own personal shopper.

Find my size

Rat & Boa is the go-to label for statement dresses, dramatic silhouettes, and contemporary glamour. But when it comes to sizing, this cult-favourite brand can be unpredictable—especially if you're shopping for slinky bias cuts, plunge gowns, or sheer fabrics that cling in all the wrong (or right) places.

In this detailed guide, we’ll break down how Rat & Boa sizing works, which styles run small or true to size, and how to find your perfect fit using Tellar.co.uk—the UK’s leading free sizing tool.

✅ First, Get Your Perfect Fit in Seconds – for Free

If you've ever ordered a Rat & Boa dress that didn’t fit quite right, you're not alone. These pieces are cut to flatter, but with minimal stretch and unconventional cuts, sizing is key.

That’s where Tellar.co.uk comes in.

Tellar matches your body measurements (or your known size in another brand) to your ideal size in Rat & Boa and 1,500+ other brands—instantly.

Here’s how to use it:

  1. Go to https://www.tellar.co.uk/create-profile/

  2. Choose your unit (CM or Inches)

  3. Enter your:

    • Chest

    • Waist

    • Hips

      (or select your size in another brand like Zara or Reformation)

  4. Instantly see your perfect Rat & Boa size

  5. Save your profile to view sizing across dozens of other luxury and high street brands

🎁 Need help measuring?

We’ll post you a free measuring tape—no strings attached.

👗 What Makes Rat & Boa Sizing Tricky?

Rat & Boa doesn’t always follow traditional UK sizing logic. The brand's signature features include:

  • Bias-cut silhouettes that cling tightly to curves

  • Sheer and satin fabrics with minimal stretch

  • Slimline sleeves and narrow bust seams

  • Dresses that often require precise chest and waist fit to drape correctly

As a result, many customers find they need to size up, especially in bust-heavy or hip-hugging styles.

General Fit Notes:

Size

UK

US

EU

XS

6

2

34

S

8

4

36

M

10

6

38

L

12

8

40

XL

14

10

42

💬 Tellar Insight: Based on our internal data, 56% of customers sized up in Rat & Boa vs. their standard high street size.

✨ Top Rat & Boa Pieces: What’s Worth Buying?

Rat & Boa dresses are designed to make an entrance. Here’s what’s consistently worth the hype—along with sizing tips for each.

1. The Gaia Dress

A best-seller. Plunging neckline, open back, and bias cut.

  • Runs small in bust

  • Size up if you’re curvier on top

  • Works best with stick-on bras or no bra

🔗 Compare with Reformation sizing

2. The Sienna Dress

Slinky satin with gathered waist detail.

  • Fits true to size if you're narrow-hipped

  • Hourglass shapes may need to size up

3. The Serafina Dress

A newer collection star. Mesh and lace with romantic flair.

  • More forgiving due to stretch

  • Take your usual size or size down for a bodycon fit

📏 Measuring Tips for the Perfect Fit

Before ordering your next Rat & Boa dress, take a few quick measurements. These are the three Tellar uses to determine your fit:

  • Chest – Measure across the fullest part of your bust

  • Waist – Measure the narrowest part of your waistline

  • Hips – Measure around the fullest part of your hips/bottom

Need help?

📮 Request a free measuring tape here or read our full how to measure yourself guide.

📉 Common Fit Issues (and How to Avoid Them)

Our users often report the following issues with Rat & Boa—and we’ve solved them with Tellar:

  • Bust too tight → Select your size based on your largest measurement, not the average

  • Hips pulling fabric awkwardly → Dresses like the Gaia or Amalfi may need one size up

  • Arms too snug → Check product descriptions for fabric composition

Tellar automatically adjusts your recommended size if one measurement (like bust or hips) exceeds typical fit ratios. That’s why our tool is more accurate than a flat size chart.

💡 How Tellar.co.uk Can Help You With All Your Brands

Rat & Boa isn’t the only tricky brand when it comes to sizing. Tellar covers all your wardrobe favourites:

Explore the entire sizing library here:

👉 https://www.tellar.co.uk/blog/

📲 Stay Updated with Tellar

We regularly post fit reviews, try-ons, and sizing comparisons across platforms. Follow us and stay in the loop:

📣 How to Get Started with Tellar.co.uk

Whether you're browsing the latest Rat & Boa drop or planning your next summer wardrobe, Tellar simplifies sizing decisions.

Your 3-step plan:

  1. Create a free profile

  2. Enter your body measurements or known brand size

  3. Get instant size matches for Rat & Boa and 1,500+ brands

🎯 “Find your size in 1,500+ brands real-time. It’s free & easy”

Final Thoughts

Rat & Boa’s dramatic style is made to turn heads—but the sizing can easily ruin the moment if you're not careful.

With Tellar.co.uk, you no longer need to second-guess. We help you shop smarter by matching your real shape to the perfect size in every brand—including this bold, confident label.

🔗 Start now—it’s free and easy

🔗 Request your free measuring tape

🔗 Explore the Tellar Sizing Library

Find my size