Adidas running shoes often feel tighter than the same Saucony size, especially in the toe box. Match both brands by foot length in centimeters, not US size alone. Saucony lists US, UK, EU, and centimeter equivalents on separate men's, women's, and unisex charts. That system helps between-size buyers pick length first, then adjust width and model.
Medical information disclaimer: This article is for general educational purposes only and does not provide medical advice, diagnosis, or treatment. Always consult a physician or other qualified health professional about symptoms, medications, tests, or treatment decisions.
Table of Contents
- Why does the same US size fit differently?
- How do you convert Adidas to Saucony?
- Which Saucony models feel roomier?
- How should the fit feel on the run?
Why does the same US size fit differently?
A running shoe last is the foot-shaped form that sets length, width, and volume. Milk and Honey Shoes explains that brands use different lasts, fit ideas, tolerances, and US, UK, and EU systems. An Adidas US 10 may therefore differ from a Saucony US 10 in length and volume.
The difference shows clearly in Adidas Ultra Boost. AIO Bot reports that the shoe technically fits true to size but runs tight in the toe box because of its Primeknit and Boost build. Reviewers advise most buyers to go half a size up for comfortable running fit in that Ultra Boost assessment.
How do you convert Adidas to Saucony?
Start with your foot length in centimeters. Step With Shoes, summarizing Saucony's official chart, notes that men's US 9 equals UK 8, EU 42.5, and 27 cm in that Saucony size chart summary. Use the same centimeter number to find your Saucony row.
Then check the correct chart for you. Step With Shoes, summarizing Saucony's official chart, lists men's US 3-16 and women's US 5-13, plus EU and centimeter equivalents. Men, women, and between-size buyers should use their own chart rather than switching US sizes directly.
Which Saucony models feel roomier?
The same Saucony size feels different by model. Sneakerjagers reports that Ride, Guide, Triumph, and Endorphin Shift offer roomier toe boxes and often wide options in that Saucony sneakers FAQ. Kinvara and Endorphin Pro racers fit narrower and suit wide feet less well.
Width choice often matters more than length inside one model. Best Walking Feet reports that the neutral daily trainer Saucony Ride 18 fits true to size with Standard, Wide, and Extra Wide versions and a PWRRUN+ cushioned ride. Pick length by centimeters, then select width for toe-box comfort.
How should the fit feel on the run?
Test fit for running, not standing. Canadian Running Magazine and MasterClass describe a running-specific check with about a thumb's width ahead of the longest toe in that running-shoe fit guide.
Feet swell and elongate on the run, so daytime length alone is not enough. Try both shoes in your running socks and compare Adidas and Saucony back to back.
- Leave about a thumb's width ahead of your longest toe.
- Keep the heel and midfoot snug without slip.
- Check toe-box width without pressure on the sides.
- Walk, jog, and bend to confirm no heel lift.