LumiSizing guide
Find your fit
Every set ships with 24 nails across a full range of sizes, so most hands can build a complete 10-nail set from a single box. Here's how to measure.
How to measure
- 01Measure the width of your natural nail bed at its widest point, edge to edge, in millimeters.
- 02Repeat for each finger — sizes commonly vary across one hand, especially between the thumb and pinky.
- 03Match each measurement to the closest size on the chart below.
- 04If you're between two sizes, size up and file down for the best fit.
Size chart
| Size | Nail bed width |
|---|---|
| XS | 10–11mm |
| S | 12–13mm |
| M | 14–15mm |
| L | 16–17mm |
| XL | 18–19mm |
Between sizes?
Size up and gently file the edges down for a precise fit — it's easier to remove material than add it. If you're consistently between two sizes across most fingers, our contact page is the fastest way to get help before you order.