Bike Tyre Size Converter
Match the confusing wheel-size names — ETRTO, inch and French — so you order a tyre that actually fits your rim.
Convert a wheel size
Reading tyre sizes
ETRTO is the truth
The ETRTO number (e.g. 37-622) is width-bead diameter in mm. The bead number (622) must match your rim — names like “28 inch” are unreliable.
Width is the first number
In 37-622, the 37 is the tyre width in mm. 700×35C means a 35 mm wide tyre on a 622 rim.
Same rim, different names
622, 700C, 29er and many “28 inch” tyres all share the same 622 mm bead — they're interchangeable on the rim.
Check clearance
A matching bead fits the rim, but frame and brake clearance limit how wide a tyre you can run.
Tyres by ETRTO/size for road, hybrid and MTB.
View on Amazon →Frequently asked questions
Is 700C the same as 29 inch?
Yes — both use a 622 mm ETRTO bead, so they fit the same rims. The tyres differ mainly in width.
What does 37-622 mean?
A tyre 37 mm wide for a 622 mm bead-diameter rim — the same as 700×37C.
How this is calculated
Tyre size is shown as ETRTO (width-bead diameter in mm), an inch description, and a French size. Only the ETRTO bead diameter reliably determines whether a tyre fits a rim — the inch and French names are approximate and overlap. A 622 bead covers 700C, 29er and most modern “28 inch” tyres.
Sources: ETRTO bead-diameter standard cross-referenced with inch and French wheel sizes, 2026.