Last Grading in Shoemaking

For shoemakers, creating comfortable, well-fitting footwear starts with one critical process: last grading. Without a thoughtful grading system, it would be impossible to design shoes that fit the wide variety of foot shapes and sizes worn by people around the world.

If every foot were identical in length and width, shoemakers would only need a single shoe last for each style. This ideal scenario would make it easy to create a last that delivers an excellent fit. But in reality, human feet vary dramatically in size, which means brands must offer multiple shoe sizes—and therefore, multiple graded lasts—to serve their customers properly.

What Is Last Grading?

Last grading is the process of creating a full range of shoe last sizes from a single base model. There are two primary grading methods used in shoemaking: arithmetic grading and geometric grading. Both systems share the same goal: to create a size range that fits as many consumers as possible, using the fewest size steps necessary.

All grading systems begin with a model last, almost always the middle size in the intended size range. From this base last, manufacturers scale up to create larger sizes and scale down to create smaller ones. The difference between arithmetic and geometric grading lies in how these size increments are calculated.

Arithmetic Grading

Arithmetic grading is the most widely used system across the UK, USA, and Europe. Under this method, each size change uses a fixed measurement increment for both length and girth.

In UK and US sizing, lasts increase by 1/3 inch (8.47mm) in length and 1/4 inch (6.35mm) in joint girth for every full size. European arithmetic grading uses smaller, metric increments: 2/3cm (6.67mm) for length and 1/2cm (5mm) for joint girth, maintaining proportional fitting similar to UK/US standards.

Because length and girth increase by set values (not percentages), larger sizes created with arithmetic grading tend to have a slimmer profile relative to their length compared to smaller sizes.

Geometric Grading

Geometric grading uses percentage-based increments rather than fixed measurements. With this system, every size change adds or subtracts a consistent percentage of the last’s overall length and girth.

When the same percentage is applied to both length and girth—such as in the historic system developed by the United Shoe Machinery Company—the last’s proportions stay identical across every size. This creates a uniformly scaled fit, rather than the slightly slimmer larger sizes seen in arithmetic grading.

Why Last Grading Matters

The way a last is graded directly impacts shoe fit. A poorly graded size range will leave customers with ill-fitting shoes, even if the base middle size is designed perfectly. Arithmetic grading remains the global industry standard for its practicality and consistent fit across everyday footwear styles, while geometric grading offers a proportional alternative for specialized design needs.

At every step of production, careful last grading ensures that shoes fit comfortably, perform well, and meet consumer expectations—regardless of foot size.