Flip-Flop Sizes: S/M/L, Paired Sizes and How They Should Fit
Flip-flops are rarely sold in single sizes. Most come in letter sizes or in pairs such as 37/38, each covering about two shoe sizes. Here is what each label typically covers and how to pick when you sit at the edge of a range.
Women's flip-flops sized S, M and L usually fit US women's 5-6, 7-8 and 9-10 (UK 3-4, 5-6, 7-8). Men's S, M, L and XL typically fit US men's 7-8, 9-10, 11-12 and 13-14. Paired sizes such as 37/38 cover two EU or Brazilian sizes; the brand's own chart says which.
- Women's S / M / L
- US 5-6 / 7-8 / 9-10
- Men's M / L
- US 9-10 / 11-12
- Brazilian size
- about EU − 2
- Sole past heel
- about 0.5-1 cm
On this page
Flip-flop size chart: S, M, L and XL
Letter sizes are not standardized. The ranges below are the ones most retailers use, with the foot lengths those shoe sizes correspond to. If a brand publishes foot lengths, trust those over the letter.
| Size | US women's | UK | EU | Foot length |
|---|---|---|---|---|
| XS | 4 | 2 | 34-34.5 | 21.2 cm / 8.3 in |
| S | 5-6 | 3-4 | 35.5-37 | 22.0-22.9 cm / 8.7-9.0 in |
| M | 7-8 | 5-6 | 38-39.5 | 23.7-24.6 cm / 9.3-9.7 in |
| L | 9-10 | 7-8 | 40.5-42 | 25.4-26.2 cm / 10.0-10.3 in |
| XL | 11-12 | 9-10 | 43-44.5 | 27.1-27.9 cm / 10.7-11.0 in |
| Size | US men's | UK | EU | Foot length |
|---|---|---|---|---|
| S | 7-8 | 6-7 | 39.5-41 | 24.6-25.4 cm / 9.7-10.0 in |
| M | 9-10 | 8-9 | 42-43 | 26.2-27.1 cm / 10.3-10.7 in |
| L | 11-12 | 10-11 | 44.5-46 | 27.9-28.8 cm / 11.0-11.3 in |
| XL | 13-14 | 12-13 | 47-48.5 | 29.6-30.5 cm / 11.7-12.0 in |
The conversions use the same scale as the shoe size chart: UK + 1 for US men's and UK + 2 for US women's.
Paired sizes: what 35/36, 37/38 and 39/40 mean
Molded rubber flip-flops are made from one mold per pair of sizes, so each label covers two EU (or Brazilian) sizes, about 1.3 cm (½ in) of foot length. Check which system the label uses: a "37/38" from a European brand is EU, while flip-flops made in Brazil are often marked in Brazilian sizes (BR), which run about 2 below EU.
| Label | If EU: US women's | If EU: US men's | If BR: equals EU | If BR: US women's |
|---|---|---|---|---|
| 35/36 | 4.5-5.5 | 3.5-4.5 | 37/38 | 6-7 |
| 37/38 | 6-7 | 5-6 | 39/40 | 7.5-8.5 |
| 39/40 | 7.5-8.5 | 6.5-7.5 | 41/42 | 9-10 |
| 41/42 | 9-10 | 8-9 | 43/44 | 11-12 |
| 43/44 | 11-12 | 10-11 | 45/46 | 12.5-13 |
| 45/46 | 12.5-13 | 11.5-12 | 47/48 | 14-15 |
So the same "39/40" label fits a US women's 7.5-8.5 if it is EU, and a 9-10 if it is Brazilian. When a listing does not say, look for the brand's foot-length chart or a second label such as "EU 39/40" printed under the BR number.
How flip-flops should fit
- Heel: fully on the sole with about 0.5-1 cm (¼-⅜ in) of sole showing behind it. This is the most important check, because flip-flops have no heel strap.
- Toes: about the same margin in front of the longest toe. Toes over the front edge catch on curbs and steps.
- Toe post: sits comfortably between the big and second toe without pressing into the web of skin. If the post rubs, the straps are pulling the foot forward: often the flip-flop is too short.
- Straps: lie across the top of the foot without digging in at the sides. A high instep needs longer straps, which some brands offer as a wide-strap version.
- Width: the outside of the foot should not spill over the sole edge at the little toe.
If your size is at the top of one pair (for example EU 38 in a 37/38), the next pair up (39/40) often fits better: rubber soles do not stretch, and the heel margin matters more than a few millimeters of extra length at the toe.
Flip-flops vs sandals and slides
Because a flip-flop is held by the toe post alone, you grip it slightly with the toes as you walk. A sole that is too long increases that gripping and slaps the ground; one that is too short pushes the heel off the back. A strapped sandal or slide tolerates a centimeter of extra length much better. For walking long distances or uneven ground, a sandal with a heel strap is the safer choice.
Kids' flip-flops
Children's flip-flops are usually sold in paired sizes such as 11/12 (US kids) or 27/28 (EU). Buy for the current foot with a small margin rather than for growth, because a long flip-flop is easy to trip on. Under about age 3, a sandal with a back strap is easier for a child to keep on. For children's size conversions see the kids' shoe size chart.
Measuring for flip-flops at home
- Stand on a sheet of paper with your heel against a wall and mark your longest toe.
- Measure heel to mark in cm.
- Add about 1.5 cm (⅝ in) for the margin at heel and toe. That is the sole length to look for.
- Compare with the sole length on the brand's chart, or lay a flip-flop you already like on the paper and measure it.
Indoor alternatives with similar letter sizing are covered in the slipper size guide.
Frequently asked questions
What size is S, M, L in women's flip-flops?
Typically S = US women's 5-6 (EU 35.5-37), M = 7-8 (EU 38-39.5), L = 9-10 (EU 40.5-42), and XL = 11-12 where offered. Brands differ by up to a size, so check the foot length on the brand's chart.
I'm a half size. Which flip-flop size should I buy?
Go to the range that puts your size in the middle or lower half. A US women's 8.5 is at the top of M (7-8), so L (9-10) usually fits better; your heel should never hang off the back.
What does BR mean on flip-flop sizes?
BR is Brazilian sizing, used by flip-flop makers from Brazil. It runs about 2 sizes below EU, so BR 37/38 is roughly EU 39/40, UK 5.5-6.5 or US women's 7.5-8.5.
Should your heel hang off a flip-flop?
No. A heel over the back edge means the flip-flop is too short. You should see about 0.5-1 cm (¼-⅜ in) of sole behind the heel and in front of the longest toe.
Are flip-flops unisex sized?
Many are. Unisex flip-flops are normally labeled in EU or men's US sizes. A women's US size is about 1.5 above men's, so a women's 8 takes roughly a men's 6.5.