Recommended tire pressure based on rider + bike weight, tire width, terrain, and load split. Quick mode for the basics; advanced mode for rim type, posture, wet pavement, average speed, and altitude/temperature correction (the gauge difference between where you pump and where you ride).
The number shown above is a range, not a single value. Within it, pressure is a comfort ↔ speed trade-off:
Stay toward the lower end of the range if any of these apply:
A few watts paid in rolling resistance is usually a great trade for staying fresh, in control, and on the bike at the end. On rough roads the lower pressure can even be the faster choice once vibration losses are counted.
Three principles drive the maths.
The Berto/Heine principle: optimal tire pressure produces about 15% vertical drop under load. Pressure scales linearly with load and inversely with width. Diameter (650b vs 700C) doesn’t matter much, measured width does.
TSS / hookless road rims must obey: ≤ 5 bar (72.5 psi) up to ~29 mm · ≤ 4.5 bar (65 psi) for 30–34 mm · ~60 psi beyond. We enforce these and warn if the recommendation hits the cap (use a wider tire if you need higher).
Pump in a 20 °C garage at sea level, then ride at 2 500 m and 30 °C, the gauge changes by ~5 psi. Optional advanced inputs use ideal-gas + standard atmosphere to compute the pump gauge that lands on your target ride gauge.
Most riders run 10–15 psi too high. Modern wide tires (28+ mm) on smooth tarmac are fastest and grippier at 50–70 psi for 70–80 kg riders, not the 100+ psi old habit. The reasons:
Test it: run the same loop at three pressures (e.g. 70, 60, 50 psi) on the same day, same gear, same route. The fastest one wins. Don’t take our word for it, the route always tells you.
For TT and triathlon athletes, pair pressure with field aero testing, the lab measures CdA + Crr in the same protocol so you can pick a tire/pressure combo that’s actually optimal for you.
For a 75 kg rider + 8 kg bike. Real numbers come from the calc above.
Smooth tarmac, dry. Front lower than rear because of weight split. Drop 5 psi for chip-seal or wet.
Wider tire, lower pressure, better real-world speed. Default for most modern road riders on rough surfaces.
Tubeless almost mandatory at this width. Lower for chunky surfaces, slightly higher if you’re mostly on hardpack.
Even lower for technical descents; even higher for hardpack / XC race. Tubeless mandatory below ~30 psi.
50/50 weight split flattens the front-rear gap. CdA testing usually beats pure pressure tweaking here.
The watts you save with better Crr show up in the power equation directly.
Open → Crr calculatorIf you have power + speed + CdA, this confirms your actual rolling-resistance number.
Open → All calculatorsBack to the full catalog, 30+ endurance calculators across performance, fueling, swim, bike, run.
Browse →Field aero testing at the lab measures CdA and Crr in the same protocol, so we can recommend the specific tire and pressure that’s optimal for your bike, body, and roads. Pays for itself in one hilly race.
Spotted a bug or want a feature? Email info@yousuli.co.
