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| Enter values to see recommendations. | |||||||
Bicycle tire pressure is the air support that keeps a tire from collapsing under the combined load of rider, bike, and gear. Too much pressure can make the bike skip and chatter over broken pavement or trail edges, while too little can feel vague and raise the chance of pinch flats or rim strikes. This calculator estimates a front and rear starting pressure for the setup you actually ride.
That matters more than it used to. Modern road, gravel, and mountain bikes span a wide range of tire widths, rim widths, and tubeless or tubed setups, so one old rule of thumb no longer fits everything. A 30 mm endurance-road tire and a 45 mm gravel tire may carry similar total weight, yet they need very different pressures to feel controlled.
The page combines system weight, tire width, rim internal width, riding category, wheel load split, surface, setup, casing, weather, and inserts to produce separate Target, Range, Safe, and Contact patch values for each wheel. It also draws a pressure map so you can see how the recommendation moves when total load changes.
That makes the tool useful both for first setup and for small equipment changes. An 82 kg endurance-road system on 30 mm tubeless tires may want a result in the high 50s front and low 70s rear, while a loaded gravel bike on 45 mm tires can land far lower because the tire volume, surface, and cargo all change what support feels right.
The result is a starting point, not a universal optimum. It does not replace the lower of your tire and rim pressure limits, and it cannot feel how your bike reacts in your own corners, rocks, braking zones, or wet pavement.
Begin with the Riding category that best matches your tire family and typical use, then enter true System weight rather than body weight alone. The tool works best when that number includes the bike, bottles, tools, pack, and any cargo that actually stays on the bike during the ride.
Front load share near the default 45 percent. That is a sensible first pass for many drop-bar bikes and keeps the rear target naturally higher than the front.Setup, Casing, Weather, and Inserts to reflect real equipment or conditions, not to force the answer toward a favorite number.Target sits above the Safe floor. For rough gravel or trail use, also watch the lower edge of Range because traction and rim protection trade off there.Bicycle Pressure Map when your load changes from ride to ride. It is especially helpful for bikepacking, commuting, or trainer versus outdoor use.The most common misread is treating the Safe window as the recommended operating band. It is not. Safe is the clamp window that prevents the tool from suggesting obviously unreasonable numbers for the entered width and setup. The actual recommendation is the Target, with Range giving a smaller tune-around zone.
If either wheel lands right on the Safe floor or ceiling, slow down and verify your printed tire and rim limits before you ride hard. Then test the Target first and adjust in small 1 to 2 psi steps from there.
The calculation starts by splitting total system mass across the two wheels. A bike rarely carries weight evenly, so the page uses Front load share to create separate front and rear wheel loads before it computes any pressure. That is why the rear recommendation usually ends up higher: it is carrying more of the same total mass.
Each wheel's base pressure grows with wheel load and falls as tire width increases. The selected riding category applies a profile factor, then terrain, priority, setup, casing, weather, rim-to-tire ratio, and inserts multiply that baseline. Those adjustment factors are bounded together, so one aggressive setting cannot push the result into absurd territory by itself.
The raw result is not shown directly. It is clamped into a width-based Safe window, then a smaller tuning band becomes Range. Tubeless setups and inserts lower the floor, butyl tubes can lift the ceiling slightly, and optional minimum or maximum overrides can tighten the window even further. That means the same rider weight can produce different answers for a 30 mm road tire, a 45 mm gravel tire, and a 2.4 inch trail tire even before surface and casing are considered.
The page also estimates Contact patch from wheel load divided by target pressure and sweeps total system weight across a wider span to draw the Bicycle Pressure Map. On that chart, the front and rear boundary lines show how the recommendation changes as total load rises, while the current setup markers show where today's input sits inside that weight-response picture.
The main pressure estimate follows one baseline equation and then applies bounded condition factors.
| Symbol | Meaning | Unit |
|---|---|---|
W |
Wheel load after front and rear split | kg |
C |
Base coefficient used by the package | 52.5 |
T |
Tire width | mm |
Fprofile |
Riding-category multiplier | factor |
Pbase |
Pressure estimate before the safe clamp | psi |
A quick road example shows how the numbers move. With an 82 kg system, a 45 percent front share gives 36.9 kg on the front wheel and 45.1 kg on the rear. On 30 mm endurance-road tires with a 21 mm rim, the package computes front and rear baselines, applies the condition multipliers, and then lands near 57.7 psi front and 70.5 psi rear before rounding for display.
The clamp rules are mostly tied to tire width, then nudged by setup details. That is why entering wider tires can lower both the recommended target and the allowed floor in one step.
| Tire width band | Safe floor | Safe ceiling | Adjustments |
|---|---|---|---|
<= 28 mm |
55 psi | 110 psi | Tubeless subtracts 2 psi from floor; butyl tubes add 2 psi to ceiling. |
29 to 32 mm |
45 psi | 95 psi | Very narrow rim-to-tire ratios can add 4 psi to the ceiling. |
33 to 40 mm |
34 psi | 78 psi | Minimum or maximum overrides can tighten the window. |
41 to 50 mm |
26 psi | 65 psi | Tubeless and inserts each reduce the floor by 2 psi. |
51 to 62 mm |
20 psi | 48 psi | The final ceiling is never allowed to fall below floor plus 8 psi. |
> 62 mm |
18 psi | 42 psi | Large-volume tires keep the broadest traction-oriented floor. |
The Range value is then built around Target, usually at about 8 percent of target pressure with width-specific caps. The lower edge is clamped back into the Safe window, so a very low-pressure setup can show a front range that almost sits on the floor even when the raw tuning band would dip under it.
| Output field | Meaning | How to use it |
|---|---|---|
Target |
Starting pressure for that wheel | Use this for the first ride before fine tuning. |
Range |
Short tuning band around the target | Move within it when you want more snap or more grip. |
Safe |
Width-based clamp window after setup adjustments | Treat it as a boundary, not a preferred riding band. |
Contact patch |
Load-over-pressure estimate | Useful for comparison across changes, not as a measured footprint. |
Bicycle Pressure Map |
Front and rear pressure curves across a weight sweep | Use it when cargo, rider mass, or bike role changes often. |
Set the bike up as honestly as you can, then use the first result as a ride-test baseline rather than the final word.
Riding category. Match the real tire family and riding style first, because that choice sets the baseline profile factor.System weight, Tire width, and Rim internal width. Include bike and gear in the weight total, not just body mass.Front load share, Surface, Priority, Setup, and Casing. If you do not know your front split, keep the default and revisit it only after a few rides.Advanced for Extra carried weight, Weather, Tire inserts, or pressure overrides. If the warning says Pressure overrides create an invalid safe window, lower the minimum or raise the maximum before expecting wheel targets.Wheel targets tab. Compare each wheel's Target, Range, Safe, and Contact patch, and note whether the rear is meaningfully higher than the front.Bicycle Pressure Map when load changes matter, then keep the first ride at the shown Target. If the bike feels harsh, reduce pressure slightly; if you feel rim taps or vague support, add pressure in small steps.Read Target as the first pressure to try, then use Range for small tuning moves around that baseline. The package expects you to compare that recommendation with your real tire and rim limits before you ride aggressively.
Safe is a clamp, not a recommendation. A wheel with Target = Safe floor or Target = Safe ceiling is already sitting on a package boundary.Range is the practical adjustment zone. If you are searching for grip, start near the lower side of that band. If you want firmer support or less tire movement, start near the upper side.Contact patch is a simplified estimate built from load and pressure. It is helpful for comparing setups, but it does not measure the exact shape touching the ground.Bicycle Pressure Map shows how pressure changes with total weight. It does not model suspension settings, sealant loss, casing wear, or temperature-driven pressure drift during a ride.A calm-looking chart does not guarantee safe handling. Verify the result against the printed pressure limits on tire and rim, then ride your usual surface and adjust by 1 to 2 psi at a time.
An 82 kg system on 30 mm tires with a 21 mm rim, the Endurance / all-road profile, Tubeless, and a 45 percent front split produces a front Target of about 57.7 psi and a rear Target of about 70.5 psi. The displayed Range sits around 53.1 to 62.3 psi front and 64.9 to 76.2 psi rear, with a shared Safe window of 43 to 95 psi. That is a classic case where the rear wheel needs more support simply because it carries more load.
A 94 kg combined bikepacking setup on 45 mm tires and a 25 mm rim, using the Bikepacking gravel profile, Loose gravel, Comfort / grip, wet weather, and inserts, lands near 24.7 psi front and 31.4 psi rear. The front Range starts around 22.2 psi and the Safe floor is 22 psi, so the tool is already telling you this setup lives close to its traction-oriented lower boundary. That does not mean the number is wrong. It means your first verification step should be a careful ride check for rim taps and sidewall stability.
A rider enters a 28 mm road setup but sets Minimum pressure override to 70 psi and Maximum pressure override to 65 psi. The page shows the warning Pressure overrides create an invalid safe window. Raise the maximum or lower the minimum. and no wheel rows are produced. That troubleshooting path is intentional: fix the clamp conflict first, then recalculate before judging any pressure recommendation.
Because the rear wheel usually carries more of total system weight. The page splits the load by Front load share before it computes each wheel's Target.
Use total system weight. That means rider, bike, bottles, tools, bags, and anything else that stays on the bike while riding.
Contact patch tell me the exact footprint on the road?No. It is a simplified load-over-pressure estimate that helps compare setups. Tire construction, speed, lean angle, and surface shape can change the real footprint.
Reduce Minimum pressure override, increase Maximum pressure override, or clear one of them. The package will not produce wheel targets when the Safe window collapses.
No. The calculations stay in the browser, so weight, tire size, and ride settings are not uploaded to a server.