Running Shoe Sizing Explained

Why Running Shoes Size Differently

Getting your running shoe size right is critical for comfort, injury prevention, and performance. Running shoes fit differently to everyday shoes because during running, your foot swells and slides forward inside the shoe.

Most running experts recommend going half a size to a full size larger than your regular shoe size. This prevents black toenails, blisters, and nail loss on longer runs.

The Thumb Space Rule

The standard fitting rule for running shoes is: you should be able to fit one thumb's width, approximately 10-12mm, between the end of your longest toe and the end of the shoe. If the shoe is too snug at the toe, go up a half size.

Should Running Shoes Be a Size Bigger?

For most Australian runners, running shoes should be half a size bigger than everyday shoes. If you run long distances, have wide feet, wear thick running socks, or often get bruised toenails, a full size bigger can be more comfortable.

A bigger running shoe should still hold your heel firmly. If your heel lifts, your arch slides, or your foot moves from side to side, the shoe is too large even if the toe length feels comfortable.

Types of Running and Shoe Fit

• Road running - Cushioned shoes; go half a size up from street size.
• Trail running - Snugger fit for control; your usual size or half size up.
• Track and sprinting - Very snug; often true to size or half size down.
• Ultramarathon - Go one full size up to account for foot swelling over many hours.

How to Measure Your Foot for Running Shoes

1. Stand on a piece of paper and trace around your foot in the afternoon, when feet are largest.
2. Measure the longest length and widest width in millimetres.
3. Use the chart above to find your AU size.
4. Add 10-12mm, or around a thumb's width, for your ideal running shoe size.

Tips for Trying Running Shoes

• Always try both shoes and lace them up fully.
• Wear the socks you plan to run in.
• Walk or jog a few steps in store to check for heel slip.
• Your heel should feel locked in without pressure on the Achilles.
• There should be no pinching across the top of the foot when laced.
• Ensure there is thumb-width space at the toe.
• Try shoes in the afternoon when feet are slightly swollen.

Popular Running Shoe Brands in Australia

• ASICS - Japanese brand, very popular in Australia, true-to-size fitting.
• Brooks - US brand known for stability; half size up recommended.
• New Balance - Available in wide widths, half size up typical.
• Nike - Runs slightly narrow; half size up often advised.
• Hoka - Maximum cushion; true to size or half size up.
• Saucony - Good for narrow to medium feet; half size up for long runs.
• Mizuno - Japanese brand with snug heel fit; true to size.
• On Running - Swiss brand gaining popularity; typically true to size.

Common Running Shoe Sizing Mistakes

• Buying the same size as your casual shoes.
• Not accounting for sock thickness.
• Trying shoes on in the morning when feet are smallest.
• Ignoring width - many brands offer narrow, standard and wide options.
• Not replacing shoes after 500-800km of running.

Running Shoe Fit FAQ

How much room should running shoes have?

Leave around 10-12mm at the front of the shoe, roughly one thumb's width. This gives your toes room when your foot swells and moves forward during a run.

Should running shoes feel tight at first?

No. Running shoes should feel secure, but not tight. A small amount of heel hold is good, but pressure across the toes, sides, or top of the foot usually means the shoe is too small or too narrow.

Is half a size up enough for running shoes?

Half a size up is enough for most short and medium-distance runners. Long-distance runners, trail runners on steep descents, and runners with swelling feet may prefer a full size up.

Do running shoe sizes vary by brand?

Yes. Nike often feels narrower, New Balance and Brooks commonly offer wide widths, and Hoka can feel roomier in the toe box. Always compare your foot length and width with the brand's current size chart.