Bike Tire Pressure Calculator
There is no single correct bike tire pressure. The right number balances your weight on each wheel, your measured tire width, the surface, and your casing. This calculator uses the Berto 15% tire-drop model to set front and rear pressure that rolls fast without bottoming the rim, then adjusts for surface, casing, and weather.
Enter your setup to get a front and rear pressure range in PSI or BAR, the watts you lose by over-inflating, and a hookless safety cap. We call the output your Pressure Plan.
EB says
15% drop
Berto tire-drop model
Enter your weight, bike, tire, and surface and hit calculate. Your front and rear pressure sweet spot and the watts lost to over-inflation appear here.
Gear up
Set pressure accurately
A pressure recommendation is only as good as the gauge you set it with. Verify low gravel and MTB numbers with a digital gauge, and go tubeless to run them safely.
- Floor pump with accurate gaugeA pressure recommendation is only as good as the gauge you set it with. Cheap pumps read high.View on Amazon →
- Digital tire pressure gaugeVerify low gravel and MTB pressures to the tenth of a psi, where a floor-pump dial is vague.View on Amazon →
- Tubeless conversion kitGoing tubeless lets you safely run the lower pressures this tool recommends for rough surfaces.View on Amazon →
- Tubeless sealantSeals small punctures at low pressure and reduces burping. Top up every few months.View on Amazon →
- Digital caliperMeasure your real inner rim width and mounted tire width so the balloon math is accurate.View on Amazon →
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How tire pressure is calculated
The Berto 15% tire-drop model sets the pressure that deflects a loaded tire about 15% of its height, the deflection that minimizes rolling resistance without letting the casing bottom out on the rim. The pressure each wheel needs rises with the load on that wheel and falls with the measured tire width. From that road baseline, this tool adjusts for surface, casing, wheel size, and weather.
| Input | Effect on pressure |
|---|---|
| Heavier rider or bike | Raises pressure (more load per wheel) |
| Wider measured tire | Lowers pressure (more air volume) |
| Rougher surface | Lowers pressure (more drop for grip and speed) |
| Stiffer casing or butyl tube | Raises pressure (resists pinch flats) |
| Wet conditions | Lowers pressure about 2.5 psi (grip) |
Bike tire pressure chart by rider weight
A 73 kg (160 lb) rider should start near 41 psi front and 62 psi rear on 28 mm road tires, or about 18 front and 27 rear on 40 mm gravel tires. Pressure rises with rider weight and falls as the tire gets wider or the surface gets rougher, so the front always sits below the rear because it carries less load. The charts below come straight from the Berto 15% tire-drop model this calculator uses, at the setups noted. They are starting points: enter your exact tire width, rim width, casing, and surface above to personalize them.
Road bike tire pressure chart (28 mm tubeless)
28 mm tire on a 21 mm internal rim, high-performance tubeless, worn pavement. Drop a few psi on chip seal or in the wet; add a few on glass smooth asphalt.
| Rider weight | Front | Rear |
|---|---|---|
| 120 lb (54 kg) | 32 psi | 48 psi |
| 140 lb (64 kg) | 36 psi | 55 psi |
| 160 lb (73 kg) | 41 psi | 62 psi |
| 180 lb (82 kg) | 46 psi | 68 psi |
| 200 lb (91 kg) | 50 psi | 75 psi |
| 220 lb (100 kg) | 55 psi | 82 psi |
Gravel bike tire pressure chart (40 mm tubeless)
40 mm tire on a 23 mm internal rim, high-performance tubeless, fast gravel. Go lower for chunky or technical terrain where grip and comfort matter more than the last watt.
| Rider weight | Front | Rear |
|---|---|---|
| 120 lb (54 kg) | 14 psi | 21 psi |
| 140 lb (64 kg) | 16 psi | 24 psi |
| 160 lb (73 kg) | 18 psi | 27 psi |
| 180 lb (82 kg) | 20 psi | 30 psi |
| 200 lb (91 kg) | 22 psi | 33 psi |
| 220 lb (100 kg) | 24 psi | 36 psi |
Mountain bike tire pressure
MTB pressure is dominated by tire volume and rim-strike risk rather than rolling resistance alone, so a single chart misleads. As a guide, most riders run the high teens to high 20s psi on a 2.25 to 2.4 in tubeless tire, with the front a couple psi below the rear, lower for loose or rocky trail and higher for hardpack or heavier riders. Use the calculator above with your tire width and surface for a personalized front and rear number, and always run tubeless to go low safely.
Want the speed payoff? Correct pressure is one of the cheapest watts in cycling. See how the savings compare to wheels and drafting in our guides to aero wheels worth the money and how much drafting saves.
What is the right tire pressure for 25, 28, 30, and 32 mm tires?
Wider tires need less pressure for the same 15 percent tire drop, so as you go up in width your pressure comes down. The baselines below are for a 75 kg (165 lb) rider on a road bike with hooked rims and tubeless tires on worn pavement. They are starting points: heavier riders add pressure, lighter riders drop it, and rough roads reward going lower still.
| Tire width | Front (psi) | Rear (psi) |
|---|---|---|
| 25 mm | 53 | 80 |
| 28 mm | 44 | 66 |
| 30 mm | 39 | 59 |
| 32 mm | 35 | 53 |
Computed live from the same Berto 15 percent tire-drop model the calculator uses. Enter your real weight, rim width, casing, and surface above for your exact front and rear numbers.
Bike tire pressure FAQ
What should my bike tire pressure be?
There is no single number: correct pressure depends on the load on each wheel, your measured tire width, the surface, and your casing. As a starting point, a 73 kg (160 lb) rider runs about 41 psi front and 62 psi rear on 28 mm road tires, roughly 18 and 27 psi on 40 mm gravel tires, and the low-to-mid 20s on a 2.25 in MTB tire. Wider tires, rougher surfaces, and tubeless casings all lower that number; more rider weight raises it.
What PSI should road bike tires be?
For 25 to 28 mm road tires on a modern wide rim, most riders land between 40 and 75 psi, not the 100-plus psi that was standard a decade ago. A 64 kg (140 lb) rider on 28 mm tires is near 36 front and 55 rear; a 91 kg (200 lb) rider is near 50 and 75. Run the front a few psi below the rear, and lower both on chip seal or in the wet. Inflating past the sweet spot makes the ride harsher and slower, not faster.
What tire pressure should a mountain bike or gravel bike run?
Wide, low-pressure tires are the whole point of gravel and MTB. On 40 mm gravel tires a 73 kg rider starts near 18 psi front and 27 psi rear for fast gravel, dropping a few psi for chunkier terrain. On a 2.25 to 2.4 in MTB tire, expect the high teens to high 20s depending on rider weight, trail, and how much you value grip versus rim protection. Always run tubeless at these pressures so you can go low without pinch-flatting.
Why is my front tire pressure lower than the rear?
Most of your weight sits over the rear wheel. On a road bike the split is roughly 40% front and 60% rear, so the rear tire carries more load and needs more pressure for the same 15% drop. Triathlon and TT positions shift slightly more weight forward (about 45/55). Running the front a few psi lower than the rear improves grip and comfort without raising rolling resistance, because the front carries less load.
Does a wider rim change my tire pressure?
Yes. A tire balloons wider on a wider internal rim, and a wider tire needs less pressure for the same 15% drop. A 28 mm tire on a 25 mm internal rim can measure 31 mm or more. This tool computes that measured width and uses it, not the labeled size, so a modern wide rim drops your optimal pressure by several psi versus an old narrow rim.
What is the maximum pressure for hookless rims?
Hookless tubeless rims are capped at 5.0 bar, which is 72.5 psi, under the current ETRTO and ISO standards. Above that the tire can blow off the rim because there is no bead hook to retain it. If your weight and tire size would call for more than 72.5 psi, run a wider tire rather than exceeding the cap. This calculator clamps hookless results at 72.5 psi and warns you when it does.
Can running too much tire pressure slow me down?
Yes, on anything but glass-smooth pavement. Above the optimal pressure the tire stops absorbing surface texture and instead bounces, so your body and bike absorb the vibration as wasted energy. This is called impedance or suspension loss. On rough gravel, over-inflating by 10 psi can cost 15 to 20 watts. On fresh asphalt the same over-inflation costs almost nothing, which is why surface choice matters as much as load.
Should I lower tire pressure in the wet?
Slightly. Dropping a couple of psi front and rear increases the contact patch and improves grip on wet roads and trails, with a negligible rolling-resistance cost. This tool subtracts about 2.5 psi from both wheels when you select wet conditions. Do not overdo it: going far below the recommended range raises pinch-flat and burping risk, especially with tubes.
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