ON Running Sizing Guide UK: How to Find Your Perfect Fit & What’s Worth Buying
Author: Stylist and brand team at Tellar
Date: 2025
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From the Swiss Alps to the streets of London, ON Running has carved out a reputation for futuristic comfort and precision design. But their technical sizing—especially across Cloud shoes, apparel, and accessories—can leave shoppers wondering, What size should I actually buy?
At Tellar.co.uk, we specialise in decoding brand sizing. Whether you’re a runner, walker, or simply a fan of ON’s minimalist aesthetic, we help you find your perfect ON size based on your body—not a generic chart.
This guide covers:
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How ON sizing works for shoes and clothing
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Common sizing issues UK shoppers face
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Best ON products worth buying
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How to get your best ON fit using Tellar.co.uk’s free tool
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Bonus: links to login, free measuring tape, and Tellar’s About Us
Why ON Running Sizes Can Be Confusing
ON’s commitment to high-performance tech means their sizing isn't always standard. Here’s why:
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Shoe fits vary by model (Cloud 5 vs. Cloudmonster vs. Cloudsurfer)
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Clothing fits tight — especially tops and jackets
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Unisex styles can run large or short depending on your frame
ON uses EU sizing converted to UK and US, but UK shoppers often report:
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Running shoes coming up small in length
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Narrow toe boxes in key models
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Leggings and jackets fitting tight around the waist or chest
Tellar.co.uk solves this with a free, smart profile tool that matches your measurements to ON’s real-world fit data.
ON Shoe Sizing: What You Need to Know
ON Running shoes are engineered for performance—so fit is everything. Here’s a breakdown by category:
🏃♂️ Running Shoes
Model |
Fit Type |
Sizing Advice |
|---|---|---|
Cloud 5 |
Standard/Narrow |
Runs small – size up 0.5 |
Cloud X 3 |
Snug/Low-volume |
Size up for wider feet |
Cloudmonster |
Wider toe box |
True to size |
Cloudsurfer |
Standard |
May run long – check width |
Tip: Most ON shoes run narrow, especially in the forefoot. If you’re a UK 6.5 with a wider foot, Tellar may recommend a UK 7 in Cloud X but stick with UK 6.5 in Cloudmonster.
📌 Use our size lookup now to see what ON Running shoe fits your feet best.
ON Clothing: Tight Fits, Technical Cuts
While ON Running shoes get all the attention, their apparel deserves notice—if you can get the right size.
Key Fit Insights:
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Tops and jackets: Slim fit with stretch; size up for layering
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Leggings and shorts: Run small in the waist
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Unisex styles: Typically boxier and longer in torso
Item |
UK Size Equivalents |
Runs Small? |
|---|---|---|
Performance T-shirt |
XS–XL |
Yes – size up |
Weather Jacket |
XS–L |
Yes – snug shoulders |
Running Tights |
XS–XL |
Yes – tight waistband |
Unisex Hoodie |
XS–XL |
No – roomy fit |
Many users report returning items that felt too restrictive—especially in the Performance range. Tellar helps reduce those returns by cross-referencing your measurements with verified ON size data.
Best ON Products Worth Investing In
ON has a cult following for a reason. Here’s what our data shows UK shoppers love the most:
★ Cloud 5 Running Shoe
Their signature model—lightweight, breathable, and stylish. Best for daily wear or light running.
★ Cloudmonster
The best choice for comfort. Larger outsole and wider fit make it ideal for longer runs or walking.
★ Weather Jacket
Ultra-light and windproof. Great for layering, but definitely size up if you’re broad-shouldered.
★ Performance-T
Sweat-wicking and structured. A bit of a tight fit—Tellar recommends checking your chest and waist measurements first.
How to Find Your Best Fit with Tellar.co.uk
We’ve made it easier than ever to shop ON Running with zero size guesswork.
✅ Step 1: Create Your Free Profile
Add your chest, waist, hips, and foot size. Or start with a brand you know fits you—like Nike or Adidas—and we’ll estimate your ideal ON size.
You’ll also get a free measuring tape shipped to your door if needed:
✅ Step 2: Search ON
Our tool checks:
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How each ON product fits
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What size suits your exact measurements
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Whether to size up/down based on your foot width or torso length
✅ Step 3: Get a Smart Fit Recommendation
We don’t just tell you to “size up.” We tell you:
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Which styles run snug
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Where you’ll feel pressure (chest, hips, toes)
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What to buy instead if ON doesn’t fit your shape
Why Shoppers Trust Tellar.co.uk
We’ve helped over 10,000 UK users find better-fitting clothes and shoes with:
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Smart brand-specific sizing
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Honest, independent advice (we don’t sell products ourselves)
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1,500+ brands covered, including Nike, Adidas, and Lululemon
And it’s totally free.
💡 Learn more about our mission
Stay Connected with Us
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You’ll get real-world fit reviews, shape-specific suggestions, and product comparisons.
Final Take: Is ON Worth It?
If you value:
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Sleek, technical design
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Lightweight, high-performance running shoes
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Minimalist athleisure with substance
Then yes—ON is worth the price tag. But only if it fits you well.
Avoid the “size roulette” with one quick profile on Tellar.co.uk.
✅ Get Started Now
Find your ON Running size in seconds. It’s Free & Easy.
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