Runfit: Runing Shoe Size Guide
Fit finder by width & feel
Free · Designed for iPad. Not verified for macOS.
Stop guessing your running shoe size. Rrunfit tells you the size to buy in the running shoe you actually want — personalized to your feet.
Every running shoe fits differently. The same "size 9" can feel snug in one model and roomy in another, because the real measurement is on the inside of the shoe, not the number printed on the box. Rrunfit is built on exactly that: 3D internal size data measured from the inside of real running shoes. Combine it with the sizes you've already worn and how they felt, and Rrunfit's AI recommends the right size for the model you're considering.
HOW IT WORKS
1) Tell Rrunfit a few running shoes you've worn and the size you took in each.
2) Add how they felt — true to fit, a little tight, or a touch loose — including length and forefoot (foot width) feel.
3) Search the model you're curious about.
4) Rrunfit's AI cross-references your data against 3D internal measurements and recommends your size, with the reasoning behind it.
WHAT MAKES RRUNFIT DIFFERENT
- Built on real internal shoe measurements, not just box sizes or generic size charts.
- Learns from the shoes you've actually worn, so the more you add, the sharper the recommendation gets.
- Personalizes by both length and forefoot width — most tools ignore width, but width is the reason a "true to size" pick can still hurt.
- Reflects your own fit feel, not an average foot.
- Covers the famous models from most major running shoe brands.
WHY IT MATTERS
Buying running shoes online is a gamble. A half-size off can mean black toenails on a long run, blisters that end a training week, or a return you never wanted to deal with. Rrunfit removes the guesswork so your next pair fits right out of the box — whether you're chasing a marathon personal best or just starting to run.
FEATURES
- Personalized size recommendation for a specific running shoe model.
- Cross-brand sizing based on the shoes you've already worn.
- Length and forefoot-width fit modeling.
- A clear explanation of why each size is recommended.
- Coverage of popular models across major running brands.
- Your worn-shoe profile that gets smarter every time you add a pair.
PERFECT FOR
- Runners buying online who can't try before they buy.
- Anyone switching brands and unsure how the sizing translates.
- People with wider or narrower feet whom standard sizing fails.
- Marathon and trail runners who need a precise, confident fit.
- Gift buyers who know a runner's usual shoe but not the new model.
FREQUENTLY ASKED
Do I need to scan my foot? No. Rrunfit works from the shoes you've already worn and how they felt — no camera, no measuring tape, no foot scan required.
Does it cover my brand? Rrunfit covers the famous models from most major running shoe brands, and the catalog keeps growing.
Why does it ask about width? Because two people with the same foot length can need different sizes depending on forefoot width and how snug they like a shoe. Rrunfit factors that in.
Is it accurate for half sizes? Yes — internal measurements plus your fit feel let Rrunfit reason about half-size differences instead of rounding.
What if I've only worn a couple of shoes? It still works, and it gets more precise as you add more pairs and fit feedback.
Lace up with confidence. Tell Rrunfit what you've worn, search the shoe you want, and get the size that fits your feet — not the average. Find your fit with Rrunfit.
Ratings & Reviews
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The developer, Yun Lee, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Yun Lee
- Size
- 58.5 MB
- Category
- Sports
- Compatibility
Requires iOS 16.2 or later and a device with the A12 Bionic chip or later.
- iPhone
Requires iOS 16.2 or later and a device with the A12 Bionic chip or later.
• iPhone XS
• iPhone XS Max
• iPhone XR
• iPhone 11
• iPhone 11 Pro
• iPhone 11 Pro Max
• iPhone SE (2nd generation)
• iPhone 12 mini
• iPhone 12
• iPhone 12 Pro
• iPhone 12 Pro Max
• iPhone 13 Pro
• iPhone 13 Pro Max
• iPhone 13 mini
• iPhone 13
• iPhone SE (3rd generation)
• iPhone 14
• iPhone 14 Plus
• iPhone 14 Pro
• iPhone 14 Pro Max
• iPhone 15
• iPhone 15 Plus
• iPhone 15 Pro
• iPhone 15 Pro Max
• iPhone 16
• iPhone 16 Plus
• iPhone 16 Pro
• iPhone 16 Pro Max
• iPhone 16e
• iPhone 17 Pro
• iPhone 17 Pro Max
• iPhone 17
• iPhone Air
• iPhone 17e
• iPhone 18 Pro
• iPhone 18 Pro Max
• iPhone Duo - iPad
Requires iPadOS 16.2 or later and a device with the A12 Bionic chip or later.
• iPad Pro (11‑inch)
• iPad Pro (11‑inch) Wi‑Fi + Cellular
• iPad Pro (12.9‑inch) (3rd generation)
• iPad Pro (12.9‑inch) (3rd generation) Wi‑Fi + Cellular
• iPad mini (5th generation)
• iPad mini (5th generation) Wi‑Fi + Cellular
• iPad Air (3rd generation)
• iPad Air (3rd generation) Wi‑Fi + Cellular
• iPad Pro (11‑inch) (2nd generation)
• iPad Pro (11‑inch) (2nd generation) Wi‑Fi + Cellular
• iPad Pro (12.9‑inch) (4th generation)
• iPad Pro (12.9‑inch) (4th generation) Wi‑Fi + Cellular
• iPad Air (4th generation)
• iPad Air (4th generation) Wi‑Fi + Cellular
• iPad (8th generation)
• iPad (8th generation) Wi‑Fi + Cellular
• iPad Pro (11-inch) (3rd generation)
• iPad Pro (11-inch) (3rd generation) Wi‑Fi + Cellular
• iPad Pro (12.9-inch) (5th generation)
• iPad Pro (12.9-inch) (5th generation) Wi-Fi + Cellular
• iPad mini (6th generation)
• iPad mini (6th generation) Wi-Fi + Cellular
• iPad (9th generation)
• iPad (9th generation) Wi-Fi + Cellular
• iPad Air (5th generation)
• iPad Air (5th generation) Wi‑Fi + Cellular
• iPad (10th generation)
• iPad (10th generation) Wi‑Fi + Cellular
• iPad Pro (11‑inch) (4th generation)
• iPad Pro (11‑inch) (4th generation) Wi‑Fi + Cellular
• iPad Pro (12.9‑inch) (6th generation)
• iPad Pro (12.9‑inch) (6th generation) Wi‑Fi + Cellular
• iPad Air 11-inch (M2)
• iPad Air 11-inch (M2) Wi-Fi + Cellular
• iPad Air 13-inch (M2)
• iPad Air 13-inch (M2) Wi-Fi + Cellular
• iPad Pro 11-inch (M4)
• iPad Pro 11-inch (M4) Wi-Fi + Cellular
• iPad Pro 13-inch (M4)
• iPad Pro 13-inch (M4) Wi-Fi + Cellular
• iPad mini (A17 Pro)
• iPad mini (A17 Pro) Wi-Fi + Cellular
• iPad (A16)
• iPad (A16) Wi-Fi + Cellular
• iPad Air 11-inch (M3)
• iPad Air 11-inch (M3) Wi-Fi + Cellular
• iPad Air 13-inch (M3)
• iPad Air 13-inch (M3) Wi-Fi + Cellular
• iPad Pro 11-inch (M5)
• iPad Pro 11-inch (M5) Wi-Fi + Cellular
• iPad Pro 13-inch (M5)
• iPad Pro 13-inch (M5) Wi-Fi + Cellular
• iPad Air 11-inch (M4)
• iPad Air 11-inch (M4) Wi-Fi + Cellular
• iPad Air 13-inch (M4)
• iPad Air 13-inch (M4) Wi-Fi + Cellular - Mac
Requires macOS 13.1 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later and a device with the A12 Bionic chip or later.
- iPhone
- Languages
- English
- Age Rating
16+
- 16+
- Contains
Unrestricted Web Access
Advertising
- Copyright
- © 슈독 주식회사