Between Shoe Sizes Guide

Complete guide on whether to size up or down when between sizes, plus solutions for perfect fit

Quick Answer: If between sizes, size UP for athletic/running shoes (need toe room for movement), size DOWN for dress shoes and heels (snugger fit preferred), and size UP for boots (need sock room). Solutions include insoles ($10-40), heel grips ($5-15), sock thickness adjustments, and lacing techniques.

Why Being Between Sizes Happens

Finding yourself between shoe sizes is incredibly common. Shoe sizing isn't an exact science - it's based on approximations and standards that vary between brands and even between different models from the same brand.

Common Reasons:

Your foot measurement doesn't match exact size increments perfectly
Feet swell throughout the day (can be 5-10% larger by evening)
One foot is often slightly larger than the other
Brand sizing varies - sizes aren't standardized across all manufacturers
Different shoe styles fit differently even in the same size

The General Rule: Size Up or Down?

When to Size UP

Athletic and running shoes: Need 0.5 inches (1.3cm) of toe room for forward foot movement
Boots: Require extra room for thicker socks and foot swelling on long days
All-day wear shoes: Feet swell during extended wear
Wide feet: Larger sizes provide slightly more width
Thick socks: If you'll wear athletic or winter socks
Feet swell significantly: Medical conditions or pregnancy
Shoes without wide widths: Sizing up gives minimal extra width

When to Size DOWN

Dress shoes and heels: Leather stretches 0.25-0.5 sizes with wear
Sandals and flip-flops: Need snug fit to prevent foot sliding
Slip-on shoes: No laces means you need snugger fit
Leather shoes: Will stretch and mold to your feet
Brand runs large: Adidas already runs 0.5-1 size large
Narrow feet: Smaller sizes are proportionally narrower

Brand-Specific Sizing Recommendations

Brand	How They Run	Between Sizes Action
Nike	Runs small/narrow	Always SIZE UP - Nike already runs 0.5 small
Adidas	Runs large/wide	Size DOWN - Adidas runs 0.5-1 size large
New Balance	True to size	Size UP for running, your preference for casual
Converse	Runs large	Size DOWN - Converse runs 0.5-1 size large
Vans	True to size	Size DOWN for slip-ons, either way for lace-ups
ASICS	Runs small	Size UP - Especially for running shoes

Check our brand-specific guides (Nike, Adidas) for detailed sizing information.

Solutions for In-Between Sizing

Solution 1: Insoles

Full-length insoles can take up 0.25-0.5 size of extra space while adding comfort and arch support. This is the best solution if you sized up and have slightly too much room.

Types:

Cushioning insoles: Add comfort and thickness ($10-25)
Arch support insoles: Provide support and fill space ($20-40)
Thin insoles: For minimal space adjustment ($10-15)

Solution 2: Heel Grips and Pads

Stick-on heel grips attach to the inside back of the shoe to prevent heel slipping in shoes that are slightly too long. Cost: $5-15 per pair. Particularly useful for dress shoes and heels.

Solution 3: Tongue Pads

Adhesive pads that stick under the tongue fill space in the instep area, preventing forward foot sliding. Great for shoes that are 0.5 size too big. Cost: $5-10.

Solution 4: Sock Thickness

The easiest free solution - adjust sock thickness to fine-tune fit:

Thicker socks: Fill extra space in slightly big shoes
Thinner socks: Provide more room in slightly tight shoes
Difference: Can make 0.25-0.5 size difference

Solution 5: Lacing Techniques

Different lacing methods can improve fit significantly:

Heel lock lacing: Prevents heel slipping in too-big shoes
Skip-lace technique: Relieves pressure for high arches
Parallel lacing: Reduces pressure for sensitive feet
Loose lacing: Accommodates slightly snug shoes

Find Your Accurate Size

Measure your feet properly and use our converter to find your true size in any brand's sizing system.

Measure Your Feet →

Shoe Type Specific Guidance

Running Shoes

Always size UP if between sizes. Running shoes need 0.5 inches (thumb width) of space at the toe. Your feet slide forward during running, especially on descents. Too-small running shoes cause black toenails, blisters, and cramped toes. The extra 0.5 size provides necessary toe room.

Hiking Boots

Size UP. Hiking downhill causes feet to slide forward. You also need room for thicker hiking socks. Toes touching the front of boots on descents causes painful injuries. Better to have slightly more room and use thicker socks or insoles.

Dress Shoes and Heels

Size DOWN, especially for leather. Leather dress shoes stretch 0.25-0.5 sizes with wear. A snug initial fit becomes perfect after breaking in. This prevents heel slipping, a common problem with dress shoes. New leather shoes should feel snug but not painful.

Sandals

Size DOWN. Your foot shouldn't hang over the edges. Sandals have no laces to adjust fit, so a snugger size prevents sliding. Foot sliding in sandals causes blisters between straps and toes.

Slip-On Shoes

Size DOWN. Without laces, slip-ons need a snugger fit to stay on your feet. Too-large slip-ons fall off while walking. The elastic or stretchy materials in most slip-ons will give slightly with wear.

Understanding Half Size vs Full Size

Half Size Difference: 1/6 inch or approximately 4.2mm. A relatively small difference that's manageable with fit solutions like insoles.

Full Size Difference: 1/3 inch or approximately 8.4mm. A more significant difference that's harder to accommodate. If you're a full size between, you'll likely need to go with the larger size and use insoles.

Width Considerations

If you're between sizes AND have wide or narrow feet, this affects your decision:

Wide Feet: Sizing up provides slightly more width. Each size increase gives approximately 3/16 inch more width. If a brand doesn't offer wide widths, sizing up half a size can help, though it's not a perfect solution. Check our shoe width guide for better options.

Narrow Feet: Can size down more easily since smaller sizes are proportionally narrower. You may also benefit from heel grips to prevent slipping in the smaller size.

Testing the Fit

When trying on shoes to decide between sizes:

Thumb Test: Press down at the toe box. There should be about a thumb's width (0.5 inches) between your longest toe and the end of the shoe. Less than this is too tight; more than 0.75 inches is too big.

Heel Slip Test: Walk around. Slight heel slip when shoes are brand new is normal and will decrease as shoes break in. Excessive slipping (more than 0.25 inches) means too big. No heel movement at all may mean too small.

Walk Test: Walk around the store for at least 10 minutes. Feet should feel comfortable without pinching, pain, or excessive movement. Try walking up stairs or inclines if possible.

Online Shopping Tip: Order both sizes if unsure. Most online retailers offer free returns. Try both at home with the socks you'll actually wear. Walk around indoors (don't wear outside) before deciding which to keep.

Break-In Period Consideration

Some shoes need a break-in period, particularly leather dress shoes. Don't immediately return slightly snug shoes if:

They're leather (will stretch)
The tightness is in width, not length
There's no pain, just snugness
You can wear them for 30 minutes without discomfort

Give new leather shoes 2-3 short wears indoors before deciding. They'll often stretch and conform to your feet. Athletic shoes typically don't need breaking in - they should feel comfortable immediately.

Last Updated: January 2025. Sizing recommendations are based on general fit standards. Always check current brand-specific sizing charts as individual models may fit differently.