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Road tire pressure for 28, 30 and 32mm tires

Published 24 September 2026

Disclosure: Pedal Brief may earn a commission if you buy through links on this page, at no extra cost to you. This version has no affiliate links. We have not tested these tires ourselves. The numbers come from our calculator's published method and the sources linked below. Full disclosures.

Who it's for: road riders on 28 to 32mm tires who want a defensible starting pressure, not a number shouted across a car park.

Short answer: for about 80 kg of rider plus bike on smooth tarmac, tubeless on a 21mm internal rim, our tire pressure calculator gives about 62 / 67 psi for 28mm, 58 / 62 psi for 30mm and 52 / 56 psi for 32mm (front / rear). Go a few psi lower on chip seal. On hookless rims, if your number lands near the limit, the fix is a wider tire, not more air.

Road tires have moved from 23mm to 28mm, and on many new bikes to 30 or 32mm. Pressure habits have not always followed. Frank Berto was already warning in 2006 that "most riders under-inflate skinny tires and over-inflate fat tires." (Berto)

How the numbers are worked out

The tables use the same method as our calculator:

• The target is 15% tire drop. Berto defined the optimum as a tire drop of "about 15% of W (the Section Width)." (Berto) Bicycle Quarterly republished his chart and stresses that the loads on it are "wheel loads, not the weight of the entire bicycle." (Bicycle Quarterly)
• A curve fit turns the chart into a formula: P = 600·L/W² + 0.75·W − 25, with P in psi, L the wheel load in pounds and W the actual tire width in mm. BikeLab Studio publishes the same fit and says it is within about 2 psi across Berto's measured range. (BikeLab Studio)
• Front at 93% of rear by default. BikeLab calibrated that ratio against SILCA and Rene Herse. (BikeLab Studio) The calculator also offers Berto's static 45/55 and 40/60 splits.
• Width is estimated from the rim unless you enter a measured width (see "Rim width moves the answer").

The formula does not know how supple your casing is or how rough your roads are. We come back to both.

Starting pressures on smooth roads

Calculator output, tubeless, 21mm internal rim, smooth surface, default split. Front / rear, psi, rounded:

These are for hooked rims. On hookless rims some of them are over the limit (see below). For bar, divide psi by 14.5. An 80 kg rider on 28mm tires is at roughly 4.3 / 4.6 bar.

One point of comparison from the industry side: Zipp engineer Mike Vittorio told SRAM he runs "30c tubeless tires on 303 S rims set at 50psi front and 52psi rear." (SRAM) He did not give his weight, so it validates nothing. It does show that low-50s on 30mm tires is normal among people who do this for a living.

Rough roads: take a few psi out

Bicycle Quarterly notes that "on very rough roads or unpaved roads, it may be useful to reduce the" pressure. (Bicycle Quarterly) Rene Herse's summary is more direct: "On rough roads, lower pressures are faster." (Rene Herse)

Vittorio put a number on it. He would "drop my pressure roughly 4psi" for rides consistently on chip seal rather than smooth blacktop, and on mixed routes he recommends erring low. (SRAM) Our calculator's "rough road" setting takes 5% off, BikeLab's rough-asphalt correction. (BikeLab Studio) For an 80 kg system on 28mm tires that is 59 / 63 psi instead of 62 / 67.

Rim width moves the answer

The same tire gets wider on a wider rim. Bicycle Rolling Resistance measured three road tires on 18, 22 and 26mm rims and found width grew "by 0.425 mm per mm increase in rim width while the height of the tires hardly changes." (Bicycle Rolling Resistance) Vittoria gives the ETRTO rule of thumb as ±0.4mm per 1mm of difference from the tire's design rim. (Vittoria)

Our calculator uses the 0.4mm rule and assumes a 19mm design rim for tires up to 28mm and 21mm for 29 to 34mm. That assumption is ours. Because the formula divides load by width squared, the effect is real. For an 80 kg system on a 28mm tire, smooth road:

If you own calipers, measure the inflated tire and type the number into the calculator's measured-width field. It replaces the estimate.

28mm, 30mm or 32mm?

The table makes one point on its own. At 90 to 100 kg, a 28mm tire wants 76 to 84 psi at the rear by this method. A 32mm tire gets the same tire drop at 63 to 70 psi. Berto's advice was plain: "Heavier people should use fatter tires." (Berto) Clearance and rim width permitting, going up a size is the cleanest way to run lower pressure without the tire bottoming out.

Hookless rims: where the table hits the ceiling

Hookless road rims have a 5 bar (72.5 psi) limit for tires up to 29mm and 4.5 bar (about 65 psi) for 30 to 34mm, per the ETRTO figures as reported by TOUR and as stated by ENVE. (TOUR, ENVE) Zipp says its hookless limit "is driven by the ISO standards for a hookless tubeless bicycle rim." (SRAM)

Read the table again with that in mind:

• 28mm: a 90 kg system wants 76 psi at the rear. Over the limit. The calculator caps it at 72.5 psi and tells you so.
• 30mm: a 90 kg system wants 70 psi at the rear, already over the 65 psi limit for that width. At 100 kg both ends are over.
• 32mm: everyone up to 90 kg stays under 65 psi on a 21mm rim. At 100 kg the rear (70 psi) is over.

TOUR's advice: "If the recommended pressure is 5 bar or more: choose wider tyres with a nominal size of 30-34 millimetres and a correspondingly lower tyre pressure." (TOUR) Hookless rims also have minimum tire widths. Taking the stricter of TOUR and the ISO Table 7 reproduced by Bicycling, a 28mm tire is below the minimum on 24mm and 25mm internal hookless rims (29mm needed). TOUR alone puts 24mm rims at 28mm, and Table 7 may not be specific to hookless rims, but we use the stricter figure. (Bicycling) None of this is verified against the ETRTO text. Our hookless tire guide has the table and the caveats.

Temperature eats into the margin. Continental puts the pressure rise at roughly 0.17 bar (2.5 psi) per 10°C. (Continental) Pump to 72 psi in a cool garage, park in the sun, and you are over.

What the formula ignores

• Inner tubes. The calculator adds 5% for tubes, BikeLab's butyl-tube correction. (BikeLab Studio) With tubes the low limit is the pinch flat, which Berto called a "snake bite." (Berto) Vittorio says that with tubeless the bottom limit is set more by impact punctures. (SRAM)
• Casing. Rene Herse, going through Berto's original data, found that supple tires "deflect much more than stiff ones, at the same pressure." It also found that for supple tires "pressure makes little difference in performance." (Rene Herse) Specific tires can sit well away from the average.
• Front and rear. Berto's 45/55 split suggests about 10% less at the front and 10% more at the rear. (Berto) Our 93% default is closer to other calculators. The tool lets you pick either.
• Your gauge. Berto found floor-pump gauges "tend to read high as they wear out." (Berto) On hookless rims, check yours against a separate gauge.

A simple way to fine-tune

Start from your number, ride a familiar loop with mixed surfaces, and change one end at a time by about 2 psi. If the bike chatters over coarse tarmac, you are probably high. If the tire squirms when you lean it over, or you feel the rim on sharp edges, you are low. Rene Herse's floor is that on pavement "your pressure needs to be high enough that the tire does not collapse during hard cornering." Otherwise: "When in doubt, let out some air." (Rene Herse)

Write down what worked, and redo it when you change tires, rims or weight.

Try it with your own numbers: tire pressure calculator. Riding gravel instead? See gravel tire pressure for 40mm tires.

What we could not confirm

• Real-world validation. The tables are model output. We have not measured tire drop or rolling speed.
• Minimum hookless widths. The stricter of TOUR and the ISO Table 7 reproduced by Bicycling, not checked against the ETRTO or ISO text. Table 7 may not be specific to hookless rims, and the two differ only at 24mm (TOUR 28mm, Table 7 29mm).
• Design rim assumptions. Our 19mm and 21mm design rims are assumptions. Real tires vary by brand.

Spot an error? Email [email protected].

Sources

• Frank Berto, All About Tire Inflation (2006): https://d-a-v-e.org/campusebikes.com/documents/Tireinflation.pdf
• Bicycle Quarterly, tire drop chart reprint: https://www.renehersecycles.com/wp-content/uploads/2015/03/BQTireDrop.pdf
• BikeLab Studio, constant-deflection model white paper: https://www.bikelabstudio.com/articles/white-paper-psi-model.html
• Rene Herse Cycles, Tire Pressure Take-Home: https://www.renehersecycles.com/tire-pressure-take-home/
• SRAM, Talking Tire Pressure for Zipp Wheels: https://www.sram.com/en/life/stories/talking-tire-pressure-for-zipp-wheels
• Bicycle Rolling Resistance, The Rim Width Test: https://www.bicyclerollingresistance.com/specials/rim-width-test
• Vittoria, Vittoria is a member of ETRTO: https://int.vittoria.com/blogs/magazine/vittoria-is-member-of-etrto
• TOUR, Hookless rims on road bikes: background and facts: https://www.tour-magazin.de/en/impellers/explosive-mix-hookless-rims-on-road-bikes-background-and-facts/
• ENVE, Hookless Rim Technology 101: https://enve.com/blogs/journal/hookless-rim-technology-101
• Bicycling, Are Hookless Wheel Systems Safe on the Road? (reproduces ISO Table 7): https://www.bicycling.com/bikes-gear/a60129869/are-hookless-wheel-systems-safe/
• Continental, Hookless vs. Hooked Rims: https://www.continental-tires.com/us/en/tire-knowledge/hookless-vs-hooked-rims/