Room, with a range
Each shoe shows how much space it leaves across your ball and past your toes, and how sure we are.
Across the ball+4.5 ± 2.4 mm
Fit without ordering three sizes
US only · $39 · Report in 48 hours
Stop guessing your shoe size.
Two photos on printer paper. You get your size and width for each foot, plus a ranked list of shoes and the millimeters of room each one leaves you.
- About a minute, no app
- Pay only after your photos pass
- #1 pick doesn’t fit? Free re-fits
The cost of guessing
“True to size” is a guess.
Size charts list length. Shoes pinch at the width, and your two feet aren't the same. Here is one runner's pair of feet against two well-reviewed shoes.
2.4 mmwider across the ball on her right foot than her left
−3.2 mmof room in the lab's top stability shoe at her size: narrower than her foot
−2.8 mmof room in a top-rated daily trainer, Saucony Ride 19 in her W9 D
Example, not a real customerSample: one runner measured for this report. Shoe numbers are RunRepeat lab interiors converted to her size.
How it works
Paper, phone, done.
Good photo · heel at the wall · 4 corners · whole foot Stand on printer paper
Paper's short edge against a wall, heel touching the wall, weight on both feet. Hold the phone flat like a tray about a foot above the paper; it shoots by itself when it's level. US Letter, or Legal if you wear a men's 10 or women's 11.5 and up.
Tell us your shoes
What you wear now and what failed. Type it on your computer while your phone shoots.
- #1 HOKA Gaviota 6 · W9.5+4.5 ± 2.4#2 HOKA Clifton 11 · W9.5+2.0 ± 2.4#3 On Cloud X · W10+2.0 ± 2.9Fit report · one time, no subscription$39.00
Pay $39, get your report
Within 48 hours: your measurements, the millimeters of room at the ball and toes with a range, and ranked picks with links.
What the report tells you
Not "fits." Millimeters.
Named risks
Rules of thumb from your numbers against the shoe's, so you know what to check when the box arrives.
Pressure at the ballShort toe roomHeel slip riskRoom across the ball
Against a shoe you own
Each pick, measured against a pair already in your closet.
Your EVO SL, at the toes71.6 mm
Altra Torin 982.2 +10.6
HOKA Clifton 1170.9 −0.7
Compare
$39 vs. the usual way
| Shoe Kung Fu | Running store | Order 3 sizes | |
|---|---|---|---|
| Cost | $39, one time | Free if you buy there* | Pay for 3 pairs, return 2 |
| Width measured | Both feet, in mm | Sometimes | No |
| Shoes compared | Lab-derived insides, across brands | What's in stock | The ones you ordered |
| Time | About a minute; report in 48 hours | A trip to the store | Days of shipping and returns |
| If it's wrong | Free re-fits until our #1 pick fits | Back to the store | More return labels |
*A store fitting costs nothing if you buy there, at their price, from their stock.
Measured, not guessed
A sheet of paper is a ruler. US Letter is always 215.9 × 279.4 mm and Legal 215.9 × 355.6 mm, so the corners turn your photo into millimeters.
Shoe labs measure one size. Interior lab data is published for a men's 9. We convert every number to your size and width.
We say when we're not sure. Ranges are estimates until our accuracy study is done. Shoes without lab interiors are labeled "estimated" and are never ranked first.
Fit guarantee
Our #1 pick doesn’t fit? We re-fit you, free.
If our #1 pick doesn’t fit, we keep re-fitting for free until it does. Tell us the shoe and size you tried and where it was tight or loose, at your 30-day check-in or any time from your report, and we send new picks.
- As many re-fit rounds as it takes.
- No return paperwork: just tell us what felt wrong.
- Automatic $39 refund if your report is late (over 48 hours).
- We don't handle shoe returns: you buy from the store, and returns go through them.
Your photos are deleted 30 days after your report, or after 7 days if you don't buy. Location data is stripped before upload, and nobody sees them unless a measurement needs a human check.
Questions
Fair questions.
What if it’s wrong?
If our #1 pick doesn’t fit, we keep re-fitting for free until it does. Tell us the shoe and size you tried and where it was tight or loose, at your 30-day check-in or any time from your report, and we send new picks. If your report is ever late (over 48 hours), your $39 comes back automatically.
Why not use the brand’s size chart?
Size charts list length. They don’t tell you how wide a shoe is inside, and your two feet differ. Two shoes in the same size can differ by several millimeters inside. We compare your measurements with each shoe’s measured interior.
Can’t a running store do this for free?
Many will measure you, and that’s worth doing. They can only compare what’s on their shelves. We compare shoes across brands by their measured insides, and you can still buy wherever you like.
What happens to my photos?
Deleted 30 days after your report, or after 7 days if you don’t buy. Location data is stripped before upload. A person sees them only if a measurement needs a second look.
What do I need?
A phone, one sheet of printer paper, a wall and a hard floor. US Letter fits most feet; if you wear a men’s 10 or women’s 11.5 and up, use Legal (8.5 × 14 in). Put the paper’s short edge against the wall and stand on it with your heel touching the wall and your weight on both feet, barefoot. Hold the phone flat like a tray about a foot above the paper; it shoots by itself when it’s level. No helper needed.
Do I take the photos barefoot?
Yes, bare feet only for now, so we measure your foot and nothing else.
Which phones work?
The guided camera runs in Safari on a current iPhone and Chrome on Android. If you tapped an ad inside Instagram, Facebook or TikTok, open the page in Safari or Chrome first. Other browsers can use the phone’s Camera app instead.
Which shoes do you cover?
Running, walking and training shoes with lab-derived interiors, modeled for your size, plus estimates for others, clearly labeled.
Do you sell shoes?
No. We link to retailers and may earn a commission when you buy. Commissions never change the ranking.
Two photos. One sheet of paper. $39.
Pay only after your photos pass. Free re-fits until our #1 pick fits.