Enter your inner rim width, rim type and tyre width to see whether the pair is within the ETRTO 2024 chart, the narrowest tyre a hookless rim takes, how wide the tyre really sits and the hookless pressure limit.
What tyre width fits a 25 mm rim? The ETRTO 2024 chart permits 29 to 71 mm tyres on a 25 mm inner rim. On a hookless rim of that width the minimum is 29 mm (ISO/ETRTO, as ENVE quotes it), so a 28 mm tyre is below it unless the wheel maker approves that exact tyre.
Inputs
Result
Within the ETRTO 2024 chart
On a 25 mm inner rim the ETRTO 2024 chart permits tyres from 29 to 71 mm. Your tyre is 29 mm.
Narrowest tyre on this hookless rim: 29 mm, from the ETRTO chart, and ENVE quotes the same ISO/ETRTO minimum for a 25 mm rim.
Actual width on this rim
The tyre maker's measuring rim for a 29 mm tyre is not stated in the sources here. Enter it in the inputs above if you know it: the width changes 0.4 mm for each millimetre the rim differs from it.
Maximum pressure
Hookless limit: 5.0 bar (72.5 psi), from the ETRTO table Schwalbe publishes for TLE/TLR tyres. Use the lowest of the three: this limit, the tyre's printed maximum and the rim's.
SAFETY: On a hookless rim fit only TLE/TLR tyres that the wheel maker approves, and never a tyre narrower than the minimum for the rim: a tyre too narrow for a wide hookless rim can come off. Use the lowest of the three pressure limits, the hookless table, the tyre and the rim. Schwalbe: "Only tires marked "TLE/TLR" (Tubeless Easy/Tubeless Ready) from the Schwalbe portfolio may be combined with hookless or straight side rims."
The chart is the ETRTO Standard 2024 as published by Schwalbe (05/2024). Your wheel and tyre makers' own lists take precedence.
Tyre and rim width chart (ETRTO 2024)
Inner rim width across, tyre width down; x marks a combination the ETRTO 2024 standard permits. ETRTO Standard 2024 as published by Schwalbe, 05/2024. Your selection is highlighted.
Tyre, mm
15
16
17
18 to 20
21 to 22
23
24
25
26 to 27
28 to 30
31 to 35
36 to 40
41 to 43
44 to 53
54 to 58
59 to 64
65 to 71
72 to 89
90 to 100
20 to 21
x
x
x
22 to 24
x
x
x
x
25 to 27
x
x
x
x
x
28
x
x
x
x
x
29 to 34
x
x
x
x
x
x
x
35 to 46
x
x
x
x
x
x
x
47 to 57
x
x
x
x
x
x
x
x
58 to 65
x
x
x
x
x
x
x
66 to 71
x
x
x
x
x
x
72 to 83
x
x
x
x
84 to 95
x
x
x
x
96 to 113
x
x
x
114 to 132
x
x
Schwalbe publishes this table on its Tire Dimensions page and adds: "The compatible types (tubeless) and tire widths specified by the wheel/rim manufacturer must be taken into account. In particular, the minimum tire widths." Continental: "Continental recommends to always follow the permitted values written on the tire packaging."
Hookless rims: minimum width and maximum pressure
The ETRTO chart applies to hooked and hookless rims alike. On a hookless rim two things are stricter. The narrowest tyre the chart permits is a floor, not a suggestion: on a 25 mm rim it is 29 mm, which is also the ISO/ETRTO figure ENVE quotes ("ISO/ETRTO recommends a 29c minimum tire size with 25mm internal rim width"). And the pressure is capped by tyre width:
Tyre width, mm
Max bar
Max psi
18 to 24
5.5
79.8
25 to 29
5.0
72.5
30 to 34
4.5
65.3
35 to 39
4.0
58
40 to 44
3.5
50.8
45 to 54
3.0
43.5
55 to 64
2.5
36.3
65 to 74
2.0
29
75 to 84
1.5
21.8
Schwalbe, for its TLE/TLR tyres, "in accordance with the ETRTO". These tires can be used both with inner tubes and tubeless on hookless rims. The same table sets the hookless warning on this site's pressure calculators.
Why the tyre is wider or narrower than the label
Continental: "For clincher tires, the width will be affected by 0.4 mm for each millimeter your rim width differs from Continental's measuring rim." Vittoria: "As a general rule, the tire width changes by ±0.4 mm for every 1 mm difference from the design rim width"; Zipp: "Many existing 700x28mm tires are designed around a 19mm internal rim width".
Continental tyre
Rim 1
Rim 2
Rim 3
Rim 4
Rim 5
Grand Prix 5000 S TR, 28 mm
15 mm: 26.4
17 mm: 27.2
19 mm: 28.0 (measuring rim)
21 mm: 28.8
23 mm: 29.6
Grand Prix 5000, 25 mm
13 mm: 24.7
15 mm: 25.5 (measuring rim)
17 mm: 26.3
19 mm: 27.1
21 mm: 27.9
Measured widths as Continental prints them. Each model has its own measuring rim, which is why the calculator only estimates the width where a maker states the rim, or where you enter it.
Read it off the ETRTO 2024 chart below: find your inner rim width and take the tyre widths marked for it. On a 19 mm rim that is 22 to 57 mm; on a 25 mm rim, 29 to 71 mm. Schwalbe: "The following table shows possible combinations of tire widths and inner rim widths according to ETRTO". The bead seat diameter has to match as well, and on a hookless rim the wheel maker's list of approved tyres comes first.
What is the minimum tyre width on a hookless rim?
On a 25 mm hookless rim, 29 mm: ENVE, "ISO/ETRTO recommends a 29c minimum tire size with 25mm internal rim width", and the ETRTO 2024 chart agrees. On narrower rims the chart's narrowest tyre is the minimum used here: 28 mm on a 23 mm rim, 25 mm on 21 mm. Wheel makers may approve narrower tyres on their own rims after their own tests: "ENVE says their 27c tire is approved for use on the same rim" (ENVE, which approves 27 mm), and Zipp says "we have partnered with select tire manufactures to validate 28mm tires for use on 303 Firecrest and 353 NSW wheels". Only the named wheel and tyre are covered by such an exception. Schwalbe: "The compatible types (tubeless) and tire widths specified by the wheel/rim manufacturer must be taken into account. In particular, the minimum tire widths".
Why is my 28 mm tyre wider than 28 mm?
Because the width on the sidewall is measured on one rim and yours is wider. Continental: "For clincher tires, the width will be affected by 0.4 mm for each millimeter your rim width differs from Continental's measuring rim". Its Grand Prix 5000 S TR measures 28.0 mm on its 19 mm measuring rim and 29.6 mm on a 23 mm rim. Zipp: "When you place most 700x28mm tires on a 25mm internal rim (like a 303 Firecrest or a 353 NSW), the tire will measure greater than 30mm". A wider tyre also sits in a different hookless pressure band, so the calculator uses the lower limit.
What is the maximum pressure on a hookless rim?
It depends on the tyre width. Schwalbe's table for TLE/TLR tyres, in accordance with the ETRTO, runs from 5.5 bar for 18 to 24 mm tyres down to 1.5 bar for 75 to 84 mm. That is one of three limits; the tyre and the rim each print their own. Mavic: "Compare them with the pressure from the chart and if they are not the same, just use the lowest of the three".
Can I fit a 2.6 inch tire on a 30 mm rim?
Yes. A 2.6 inch tyre on 584 mm rims is 65 mm or 66 mm wide in ETRTO terms, depending on the maker, and the ETRTO 2024 chart permits 65 mm on 21 to 35 mm rims and 66 mm on 25 to 43 mm rims. On a hookless rim the limit for that width is 2.0 bar (29 psi).
Last updated: November 2026
Where these numbers come from
The tyre and rim width chart (ETRTO Standard 2024, transcribed by hand from the table Schwalbe publishes) and the minimum width rule: Schwalbe.
Hookless: TLE/TLR only, the pressure table and the 25 mm minimum: Schwalbe, ENVE, Zipp.
Actual width on a different rim: Continental, Vittoria, Zipp.
Use the lowest of the tyre, rim and table limits: Mavic.
Site convention: the clearance margin, 6 mm in total beside the tyre. No frame or tyre maker read here publishes one.