What’s My Clothes Size at GAP? Does GAP Run Big or Small?

GAP is a global fashion brand known for its clean basics, laid-back denim, soft cotton tees, and timeless American classics. Whether you're after a logo hoodie, high-rise jeans, slouchy knits, or casual dresses, GAP delivers affordable wardrobe staples with wide appeal.

But one sizing question still lingers—especially for UK shoppers:

Does GAP run big or small?

And how can you confidently pick the right size when ordering online?

This guide explains how GAP sizing works by category—and introduces Tellar.co.uk, the UK’s leading free sizing tool that calculates your correct GAP size in real time, based on your body shape and the garment’s fit.

Does GAP Run Big or Small?

GAP tends to run large, particularly in:

Tops and T-shirts
Sweatshirts and hoodies
Casual and loungewear

However, some items—especially jeans, trousers and dresses—run closer to true to size, or even slightly small depending on the fit (e.g. skinny, bodycon, or structured).

Key observations:

Unisex sweatshirts and tees run generously
Women’s jeans can feel snug at the waist or hip depending on stretch
Button-up shirts and poplin dresses often need careful sizing if you’re fuller-busted

If you’re between sizes or prefer a more tailored look, it’s often best to size down in relaxed styles, and size up in fitted items made from rigid fabrics.

Why GAP Sizing Feels Inconsistent

1. American Sizing Standards

GAP uses a US fit block, which generally:

Allows for a looser silhouette
Prioritises comfort over tailoring
Assumes average height and shoulder width

This can make garments feel larger than UK or European equivalents—especially in casual categories.

2. Relaxed Fit Philosophy

GAP designs are built for everyday ease, so many items are:

Boxy or longline
Slightly oversized in the torso
Designed for layering or movement

3. Variable Denim Sizing

Different jeans styles fit differently:

High-rise skinny jeans often run small
Mid-rise straight or girlfriend jeans run true to size
Wide-leg and relaxed denim can feel generous at the waist or thigh

GAP Fit Overview by Garment Type

Garment Type	Fit Pattern	Tellar Sizing Tip
T-shirts & polos	Boxy, roomy	Size down for neater fit
Sweatshirts & hoodies	Oversized, unisex fit	Size down unless layering
Button-down shirts	True to size or slim	Size up for bust/shoulder comfort
Jeans (skinny/high-rise)	Snug at waist and thigh	Size up if curvy or between sizes
Straight-leg & boyfriend jeans	Relaxed and generous	Stick to size or down if loose at waist
Casual dresses	Flowy and forgiving	Stick to size or size down for fitted look
Tailored or poplin dresses	Closer at bust/waist	Size up for curves or fuller bust
Coats & jackets	Generous, layering-ready	True to size

GAP UK Size Conversion Chart

UK Size	GAP Size	Bust (cm)	Waist (cm)	Hips (cm)
6	XXS	80	63	88
8	XS	84	67	92
10	S	88	71	96
12	M	92	75	100
14	L	97	80	105
16	XL	102	85	110

GAP often uses lettered sizing (XS–XL), so you’ll need to translate your UK dress size carefully. Still, this conversion doesn’t tell you:

If the garment is cut oversized or slim
How stretch affects the sizing
How your body shape influences fit

That’s where Tellar.co.uk comes in.

Tellar.co.uk: The Fastest Way to Find Your GAP Size

Tellar.co.uk is a free UK sizing tool that uses your real body measurements to calculate your best GAP size—based on fit category, fabric type, and your personal proportions.

No more relying on charts, reviews, or over-ordering.

How It Works

Visit www.Tellar.co.uk
Create your free profile
Enter your bust, waist and hips (in cm or inches)
Select GAP from the brand list
Instantly see your correct size across all GAP garment types—tees, jeans, shirts, jackets and more

Once set up, Tellar also works across 1,500+ UK and global brands.

Why Tellar Is Perfect for GAP

✅ Knows the Fit Logic

Tellar adjusts your size recommendation based on how GAP items actually fit, not just what the label says.

✅ Fabric-Sensitive

Stretch denim? Woven cotton? Tellar adapts based on how rigid or flexible the fabric is.

✅ Matches by Proportions

Your most relevant body area determines the size—for example:

Bust for fitted shirts
Hips for jeans
Waist for dresses

✅ One-Time Setup

Once your measurements are entered, Tellar automatically gives you accurate sizing across every category and brand.

✅ Completely Free

No subscriptions. No paywalls. Just real-time sizing that works.

Example: UK Size 12 Shopper

Measurements:

Bust: 91cm
Waist: 74cm
Hips: 101cm

Tellar might recommend:

GAP cotton tee: Size S (roomy cut)
GAP zip hoodie: Size S
GAP poplin shirt dress: Size M
GAP skinny jeans (rigid denim): Size M / UK 14 (for hip comfort)
GAP wide-leg jeans (stretch): Size S / UK 12 (relaxed cut)

Every recommendation includes a brief explanation so you understand why that size fits your shape best.

Not Just for GAP

Your Tellar profile also gives instant sizing for:

Uniqlo
H&M
Zara
COS
Levi’s
Barbour
Jack Wills
Me+Em
…and 1,500+ brands worldwide

Final Thoughts

GAP sizing runs slightly large overall, particularly in tees, sweatshirts and outerwear. But trousers, dresses and denim can fit snug—especially when made from structured or rigid fabric.

Tellar.co.uk removes all the guesswork. It gives you real-time, garment-specific size recommendations based on your measurements and GAP’s true fit logic—so you always order the right size the first time.

“Find your size in 1,500+ brands real-time. It’s Free & Easy.”

Try it now:

👉 Create your free profile

👉 Log in anytime to view your GAP size instantly

Instagram: @Tellarsizing

Pinterest: TellarSizing

Twitter (X): @TellarSizing

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UK Size	GAP Size	Bust (cm)	Waist (cm)	Hips (cm)
6	XXS	80	63	88
8	XS	84	67	92
10	S	88	71	96
12	M	92	75	100
14	L	97	80	105
16	XL	102	85	110

UK Size	GAP Size	Bust (cm)	Waist (cm)	Hips (cm)
6	XXS	80	63	88
8	XS	84	67	92
10	S	88	71	96
12	M	92	75	100
14	L	97	80	105
16	XL	102	85	110

UK Size	GAP Size	Bust (cm)	Waist (cm)	Hips (cm)
6	XXS	80	63	88
8	XS	84	67	92
10	S	88	71	96
12	M	92	75	100
14	L	97	80	105
16	XL	102	85	110