The secret behind the fit: the last
Every sneaker is built around a last; a 3D shape that defines the length, width, and overall feel of the shoe.
Different brands use different lasts, which means sizing is never just about the number on the box.
At Mercer, consistency matters. Each model is made in one dedicated factory, helping us create a reliable fit across every pair.
It’s not just about length
Your perfect fit also depends on:
- Shape: Some sneakers are narrow, others give your toes more room.
- Materials: Leather adapts over time, while other materials keep their original shape.
- Width: A comfortable fit needs enough space to move naturally.
Our sneakers are built on a D width last, the standard width for men’s footwear and a comfortable, universal fit for women.
A small tip: measure both feet
Most people don’t have two identical feet. One foot is often slightly bigger than the other.
Measure both feet, and always choose your size based on your larger foot.

How to get your Mercer size right
1. Measure your feet
Stand up, measure from heel to toe, and do this later in the day when your feet are at their largest. Add around 0.5–1 cm for movement and sock space.
2. Check our fit notes
We test every model and share if a sneaker runs smaller, larger, or true to size on the product page.
3. Still unsure? Ask us
Send us a message. We’re happy to help you compare your current sneakers and find your best Mercer fit.
Because the right size isn’t just a number... It’s the feeling of a sneaker you never want to take off.