Measure both feet from heel to the longest toe, then enter the larger
measurement below.
Recommended Size
EU—
US Size—
UK Size—
Foot Length—
This recommendation is based on foot length. Product fit may vary by
style. Please review the product description for fit notes.
Size Conversion Chart
EU
US
UK
18
3.5
2.5
19
4–4.5
3.5
20
5
4
21
5.5
4.5
22
6–6.5
5–5.5
23
7
6
24
7.5–8
6.5–7
25
8.5
7–7.5
26
9–9.5
8–8.5
27
10–10.5
9–9.5
28
11–11.5
10–10.5
29
12–12.5
11
30
12.5–13
11.5–12
31
13–13.5
12–12.5
32
1 Youth
13–13.5
33
1.5–2 Youth
1 Youth
34
2.5–3 Youth
1.5–2 Youth
35
3.5 Youth
2.5 Youth
36
4–4.5 Youth
3–3.5 Youth
How to Measure
Place the child’s heel against a wall.
Have the child stand with toes resting flat.
Measure from the heel to the longest toe.
Measure both feet and use the larger measurement.
When between sizes, choose the next size up.
Product Details
Splash into adventure with Kai water shoes—light, breathable, and built for little feet on the move! Designed with grippy soles they keep little feet safe and secure on every sunny adventure.
Approved by the American Podiatric Medical Association for promoting healthy foot development.
37 reviews
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5 stars: 33 (89%)
4 stars: 4 (11%)
3 stars: 0 (0%)
2 stars: 0 (0%)
1 star: 0 (0%)
Some of the reviews shown are from related products the merchant grouped with this one.
O
Oxana
Comfortable, flexible. Timely delivery.
M
Merilyn Oliveros
Bought a pair for my 6 year old son, he wears them to the pool and the beach and they work great, easy to put on and remove and they dry quickly. My son states they are comfortable.
G
Georgette Friedmann
I bought these for my 2 year old grandson. I love them easy on and off. He walks around just fine in them no tripping. He has room to grow too.
M
Mehriban Hajiyeva
I really liked them! My son doesn’t want to take them off because they’re so comfortable. 😊
C
Cecilia Angyal
Luv the shoe. Excellent quality
A
Anonymous
My Granddaughter's favorite water shoes! This is the second pair I have purchased. Very comfortable and well designed, nice color choices, supports and protects feet very well. Cute, stylish and versatile! Highly recommend!
T
Terence Jones
They look really great, can’t wait for my 4 year old to give them a workout!
A
Amber
My 2 1/2 year old granddaughter just loves them. She was so excited when she open the box and put them on. She has been running around and jumping off the steps like a world class athlete.
O
Olena Kara
Good quality!
A
Anonymous
They look like they will dry well for summer wear. We are returning because my daughter says the Sahara Flex we had last summer were more comfortable.
I
Isabella Monroe
Excellent Bright Orange Sneakers
These orange Kai Flex shoes are fantastic. My 5-year-old daughter can play for hours comfortably. Great flexibility, supportive fit, and the energetic orange color looks great with her spring outfits.
I
Indigo Hart
Best Pink Sneakers Yet
These pink Kai Flex shoes are ideal for my active 5-year-old daughter. Super flexible, lightweight, and the vibrant pink makes them stand out in a cute way. She chooses them over all her other shoes.
S
Serena Vale
Energetic Purple Flex Shoes
My 4-year-old daughter chooses these purple Kai Flex shoes every morning. The flexible sole supports natural movement, and the vibrant purple color brings so much joy. Comfortable from the first wear.
L
Lyra Sage
Fun and Comfortable Pink Flex
These pink Kai Flex sneakers are fantastic. My 5-year-old can play for hours without any discomfort. Great flexibility and the bright pink color brings a smile to her face every morning.
A
Ava Harrington
Vibrant Orange Everyday Shoes
The orange Kai Flex shoes have become my daughter’s go-to pair. Lightweight, breathable, and the flexible sole is perfect for running around. The orange color stays vibrant after lots of wear.
L
Lyra Sage
Purple Kai Flex Sneakers
These purple Kai Flex sneakers are fantastic. My 5-year-old can play for hours comfortably thanks to the flexible sole. The purple color is bright and still looks fresh after weeks of wear.
E
Emma Langston
Cheerful Orange Flex Shoes
We’re very happy with the Kai Flex in orange. My 6-year-old finds them incredibly comfortable for school and play. Flexible design, good cushioning, and the bright orange color makes her smile.
C
Celeste Quinn
Lovely Pink Everyday Shoes
These pink Kai Flex shoes have become my daughter’s go-to pair. Lightweight, breathable, and the flexible sole is perfect for running around. The soft pink color is pretty and stays vibrant.
C
Celeste Quinn
Love the Purple Flex
These purple Kai Flex shoes have become my daughter’s favorite. Lightweight, breathable, and the flexible sole is perfect for daily play. The rich purple color is vibrant and fun.
A
Aurora Vale
Adorable Pink Flex Sneakers
We’re thrilled with the Kai Flex in pink. My 6-year-old finds them super comfortable. Flexible design, good cushioning, and the vibrant pink matches so many of her spring outfits beautifully.
A
Aurora Vale
Stylish Purple Shoes
We’re very happy with the Kai Flex in purple. My 6-year-old finds them incredibly comfortable. Flexible design, good cushioning, and the purple color coordinates beautifully with her outfits.
M
Mia Whitaker
Cute and Flexible Orange Shoes
These orange Kai Flex sneakers are excellent for my 4-year-old. The flexible sole bends easily with every step, and the vibrant orange shade is fun without being too loud. True to size and comfortable.
Z
Zara Bloom
Perfect Flexible Pink Shoes
These pink Kai Flex shoes are excellent for my 4-year-old. The flexible sole bends naturally with every step, and the pretty pink color is eye-catching. True to size and very comfortable for all-day wear.
Z
Zara Bloom
Fun Purple Flex Shoes
These purple Kai Flex shoes are excellent for my 4-year-old. The flexible sole bends easily with every step, and the purple color is eye-catching yet not too bright. True to size and very comfortable.
O
Olivia Fairmont
Favorite Orange Sneakers
My daughter loves wearing her orange Kai Flex shoes every day. They’re super flexible and supportive for active play. The bright orange color is energetic and easy to spot. Breathable and easy to clean.
N
Nova Sterling
My Daughter’s Favorite Pink Shoes
My little girl loves her pink Kai Flex sneakers. They’re incredibly flexible and supportive for daily play. The bright pink shade is fun and feminine. Breathable material keeps her feet cool all day.
N
Nova Sterling
Beautiful Purple Sneakers
My daughter loves her purple Kai Flex sneakers. They’re super flexible and supportive for active play. The vibrant purple shade is pretty and goes with many outfits. Breathable material keeps her feet cool.
I
Indigo Hart
Perfect Purple Playtime Shoes
These purple Kai Flex shoes are ideal for my active 5-year-old daughter. Super flexible, lightweight, and the vibrant purple makes them stand out in a fun way. Highly recommend!
L
Luna Evergreen
Bright Pink Flex Sneakers
These pink Kai Flex shoes are so cheerful and cute for my 5-year-old daughter! The flexible sole lets her run and play freely, and the vibrant pink color makes her outfits pop. Super lightweight and comfortable.
L
Luna Evergreen
Vibrant Purple Flex Sneakers
These purple Kai Flex shoes are so colorful and fun for my 5-year-old daughter! The flexible sole lets her run naturally, and the rich purple color looks amazing. Lightweight and comfortable all day.
S
Sophia Kensington
Vibrant Purple and Teal Sneakers
These purple/teal Kai Flex shoes are so colorful and fun for my 5-year-old daughter! The flexible sole lets her run naturally, and the purple with teal accents look amazing. Lightweight and comfortable all day.
S
Sophia Kensington
Bright Orange Flex Shoes
These orange Kai Flex shoes are so fun and cheerful for my 5-year-old daughter! The flexible sole lets her run and play naturally, and the vibrant orange color brightens up her outfits. Lightweight and very comfortable all day.