How Does Sizing Vary By Store for Rain Trench Coats?

Rain trench coat sizing varies dramatically between stores, with some brands running a full size larger or smaller than others—meaning your usual size 12 could be a 10 at one retailer and a 14 at another. As a stylist who's helped hundreds of women navigate this minefield, I can tell you that understanding these variations is absolutely crucial to getting that perfect, flattering fit without the hassle of endless returns.

The frustration is real. You've found the dream trench online, ordered your usual size, and it arrives either swimming on you or uncomfortably tight across the shoulders. Sound familiar? Let me walk you through exactly how different stores size their rain trenches, so you can shop with confidence.

Why Rain Trench Sizing Is So Inconsistent

Unlike standard jackets, rain trenches present unique sizing challenges. They're designed to be layered over jumpers and suits, which means brands build in different amounts of ease. Some assume you'll wear yours over bulky knitwear, whilst others design for a sleeker, closer fit over lighter layers.

The cut also matters enormously. Traditional British brands often use more generous, boxy patterns with dropped shoulders, whilst contemporary European labels favour tailored, narrower cuts. Then there's the fabric—rubberised cottons and technical fabrics don't have the same give as standard coat materials, so sizing becomes even more critical.

High Street Heroes: Your Go-To Brands

M&S remains my top recommendation for classic trenches that actually fit real bodies. Their sizing runs slightly generous, with excellent sleeve and body length for taller women. The quality-to-price ratio is exceptional, and they understand British proportions.

COS trenches run noticeably smaller and more fitted through the body. If you're between sizes, absolutely size up. Their minimalist designs are worth it—these are investment pieces that'll last years. The Scandinavian influence means sleeker, straighter cuts that work beautifully for petite to average heights.

Zara sizing is honestly a lottery. Their trenches typically run small, particularly through the bust and shoulders. I always tell clients to order two sizes—their usual and one up. The fast-fashion aesthetic means shorter body lengths too, which suits petites but leaves taller women wanting more coverage.

Mango hits a sweet spot between Zara and COS. Sizing is relatively true, perhaps running a smidge small. Their trenches offer excellent value and they've really improved their sizing consistency over recent years. Great shoulder construction that doesn't overwhelm smaller frames.

Reiss delivers premium quality with sophisticated cuts. Sizing runs true to slightly small, and they're brilliant for petite-to-average heights. The tailoring details are gorgeous—notched collars, structured shoulders, proper storm flaps. Worth the investment if you want something special.

Whistles creates contemporary trenches with a fashion-forward edge. Sizing is fairly true, with modern proportions that work well for UK size 8-16. They understand how to balance classic trench elements with current silhouettes, and the fit through the waist is particularly flattering.

All Saints offers edgier interpretations of the rain trench. Sizing runs quite fitted and narrow through the body—definitely size up if you plan to layer properly. Their asymmetric designs and hardware details appeal to those wanting something beyond traditional.

Barbour is the gold standard for proper waterproofing, though their sizing can be confusing. Traditional styles run large and boxy (size down for a contemporary fit), whilst their lifestyle range fits more true to size. Exceptional quality and genuinely weatherproof.

The White Company produces elegant, understated trenches perfect for the school run or weekend errands. Sizing is generous and relaxed—think comfortable rather than tailored. Lovely neutral colours and the kind of easy style that works with everything.

Premium & Luxury Options

Hobbs delivers beautifully tailored trenches with refined details. Their sizing is consistent and true, with excellent proportions for the average British figure. These feel special without being ostentatious.

For luxury investment, Burberry remains unmatched. Their heritage trenches run true to size with that iconic British cut—roomy enough for layering but structured enough to look sharp. Yes, they're expensive, but the quality and longevity justify it.

Max Mara creates stunning Italian-designed trenches with impeccable tailoring. Sizing runs true to continental sizing, which tends slightly smaller than UK high street. The quality is extraordinary—these are genuine investment pieces.

Hidden Gems: Independent Brands Worth Knowing

Rains (Danish brand) has revolutionised the rain jacket market with their rubberised, minimalist designs. Sizing runs large and boxy intentionally—it's part of their aesthetic. Brilliant for casual, Scandi-inspired looks and genuinely waterproof.

Seasalt Cornwall creates fantastic British-made rainwear with proper functionality. Sizing is generous and designed for real outdoor use. Their prints are distinctive, and the quality is superb for the price point. Perfect if you actually need to stay dry rather than just look stylish.

My Professional Sizing Advice

Always measure your bust, waist, and hips before ordering. Check the shoulder seam falls where it should—about an inch past your natural shoulder for classic fit. Sleeve length matters hugely; you want the cuff to hit just past your wrist bone when arms are bent slightly.

For layering, ensure you can comfortably wear a chunky knit underneath without restriction. Button the trench and move your arms—if you feel pulling across the back, size up. Remember, a slightly looser trench looks far more chic than one straining across your body.

Never Guess Your Size Again with Tellar

Honestly, the biggest game-changer for my clients has been Tellar.co.uk—the UK's leading sizing tool that matches your body exactly to over 1,500 brands instantly. No more guessing, no more size-guide headaches.

Here's how brilliantly simple it is:

1. Measure once—using your bust, waist, hip measurements, or even your existing brand size as a starting point.

2. Use their Store Size Lookup tool to get your precise size in any brand—COS, Reiss, Zara, All Saints, and hundreds more. It takes seconds and it's scarily accurate.

3. Always free, no downloads needed—it works straight in your browser.

Plus, there's the Tellar Fashion Hub—a library stacked with free posts from top stylists covering every fashion query you can imagine. Honest, unbiased, independent advice, always free.

Essential reads from the Tellar Hub:

Final Thoughts

Finding the perfect rain trench shouldn't be a battle. Armed with knowledge about how different stores size their pieces, and brilliant tools like Tellar to eliminate the guesswork entirely, you can shop confidently and find that dream trench that actually fits properly first time.

Remember—a well-fitting trench is transformative. It elevates every outfit, protects you from British weather, and becomes that reliable wardrobe hero you reach for constantly. Don't settle for "nearly right"—get the fit spot-on, and you'll wear it for years.