Best Brands for Summer Dresses (and How to Find the Right Fit Every Time)

There’s nothing quite like the ease of slipping on a summer dress. Lightweight, effortless, and instantly polished—it's the one item that manages to look put together even on the hottest, laziest days of the year.

But here’s the catch: finding a summer dress that actually fits well is harder than it should be. You try your usual size, but it’s suddenly too snug at the bust, or drowning you in fabric. One brand’s size 10 feels like an 8, while another’s size 10 fits like a 12.

Sizing across fashion brands is inconsistent at best—and that’s exactly why I now use Tellar.co.uk to check my size before I buy anything online.

Before I explain how Tellar works (it’s free, by the way), let’s run through my go-to brands for summer dresses in 2025—plus a realistic look at how each one fits.

1. Reformation

Sustainable, flattering, and event-ready—Reformation has perfected the art of the linen wrap dress. Their silhouettes tend to hug the waist and accentuate curves with just enough structure to feel polished.

Fit tip: Reformation runs small, especially around the bust and ribs. If you’re in between sizes, size up.

🟩 Use Tellar to check your Reformation size here

2. Mango

Mango consistently delivers Mediterranean-inspired dresses that work for everything from office days to summer holidays. You’ll find cotton shirt dresses, elegant halternecks, and breezy maxis all in one place.

Fit tip: Mango sizing tends to run slightly small, particularly in more structured styles with zips or belts.

🟩 Find your Mango size with Tellar

3. COS

If your summer style is clean, minimalist and intentionally oversized, COS will speak to you. Their summer collections are filled with sculptural cuts, crisp poplin, and cotton jersey blends.

Fit tip: COS runs large. Most styles are oversized by design, so if you’re between sizes, it’s worth sizing down—or letting Tellar decide for you.

4. Nobody’s Child

One of the most exciting British labels right now, Nobody’s Child is affordable, size-inclusive and increasingly sustainable. Their floral smocks and shirred midis feel instantly summery.

Fit tip: Nobody’s Child fits true to size and has some flexible features like smocking or elasticated waists.

5. & Other Stories

Effortless Parisian-meets-Scandi chic. & Other Stories is ideal if you want something a little more dressed-up without going formal. Their puff-sleeve dresses and open-back cotton midis are seasonal standouts.

Fit tip: Generally true to size, though bust and shoulder fit can vary slightly between collections.

6. Free People

If your summer wardrobe leans bohemian, Free People is unmatched. Think gauzy fabrics, embroidered hems, oversized shirt dresses and flowing maxis made for heatwave layering.

Fit tip: Many styles are intentionally oversized, but fitted dresses (especially those with zips) can run small.

7. Massimo Dutti

Structured, refined, and quietly luxurious, Massimo Dutti makes elegant summer dresses that you’ll wear for years. Their use of premium linen and crepe makes even the simplest silhouette feel expensive.

Fit tip: Massimo Dutti tends to run small, especially in fitted tailoring or belted styles.

🟩 Use Tellar to confirm your Massimo Dutti size

8. H&M

It’s fast fashion, yes—but when you need an affordable beach cover-up or a last-minute BBQ dress, H&M always has options. Their summer offerings range from slinky slips to cotton tiered dresses.

Fit tip: Sizing varies. Their main collections are often true to size, but trend-led styles can run small.

Why It’s So Hard to Get the Right Fit

Here’s the reality: there’s no such thing as a universal size chart. One brand’s UK 10 might be another brand’s 8—or even a 12.

Sizing depends on the brand’s country of origin, their design fit model, the fabric used, and even the specific collection. That means you can’t rely on the number on the label—you need a smarter approach.

How Tellar.co.uk Solves the Sizing Problem

Tellar.co.uk is the UK’s leading free sizing tool, designed to take the guesswork out of shopping for clothes online.

Here’s how it works:

You enter your body measurements (bust, waist, hips)
Or tell Tellar what size you usually wear in a brand you already own
It instantly recommends your best-fitting size across 1,500+ fashion brands

This includes Reformation, COS, Zara, Mango, & Other Stories, Massimo Dutti, Nobody’s Child, H&M, Free People and more.

✅ Works for both women’s and men’s fashion

✅ Adjusts for brands that run small or large

✅ No password needed—just a one-time email login

✅ Completely free

✅ Free printable measuring tape available here

🟩 Create your free sizing profile now

🟩 Check your dress size in any brand instantly

Why I Use Tellar Every Time I Shop

Before using Tellar, I returned nearly 40% of my online fashion purchases. Most of those returns were down to sizing—and the hassle of guessing between an S or M, an EU 38 or 40, or a size 10 or 12.

Now, I just check the brand in Tellar before I buy. It tells me:

✔ whether the brand runs small, large, or true to size

✔ what size I need based on my own body

✔ which fit will be the most comfortable and flattering

It’s completely changed how I shop—especially for seasonal items like summer dresses, where different fabrics and cuts make sizing even more unpredictable.

Stay Connected with Tellar

Tellar isn’t just a tool—it’s a growing community of fashion-savvy shoppers who want less waste, fewer returns, and better fit.

For tips on sizing, new brand updates and seasonal guides:

Final Word

There are so many great brands making beautiful summer dresses—but if they don’t fit, you won’t wear them. That’s the reality. With Tellar.co.uk, you no longer have to choose between style and certainty.

Get the right fit every time. Feel confident in what you wear. And spend less time returning clothes that never should’ve landed in your basket.

🟩 Try Tellar for free here – because summer dressing should be easy.