Bicycle Tire Pressure Calculator

Cold pump targets

Front {{ wheels[0].pumpPsiDisplay }} / Rear {{ wheels[1].pumpPsiDisplay }}

{{ wheels[0].projectedRidePsiDisplay }} front · {{ wheels[1].projectedRidePsiDisplay }} rear expected on-road

Check your inputs

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Riding category:

Pick the profile whose usual tire range matches your measured casing width.

System weight:

Enter total ride weight, then choose kg or lb in the same row.

Measured tire width:

Use calipers after inflation, e.g. 30.5 mm for a 700x30 tire.

Rim internal width:

Enter the internal rim width printed by the maker or measured between bead hooks.

Wheel size:

Select the diameter fitted to this tire, not a spare wheel size.

Surface:

Choose the roughest surface that will dominate the ride.

Ride feel:

Use Balanced for a neutral start; choose comfort or speed to bias the target.

Setup:

Select the setup mounted for this ride, including tube material when applicable.

Extra carried weight:

Enter only extra luggage or cargo not already counted above; use 0 otherwise.

Casing:

Choose supple, standard, reinforced, or insert-ready sidewalls.

Weather grip:

Leave Dry or mild unless the ride is wet/cold or hot pavement.

Load split:

Keep Auto unless you have a measured or well-known front load share.

Front load share: {{ front_load_percent }}%

Move 38%-52%; lower values mean more rear load and rear pressure.

Tire inserts:

Switch on only when foam inserts are installed in the wheels being ridden.

Inflation temp:

Enter -20 to 50°C for the place you inflate the tires.

°C

Ride temp:

Enter -20 to 50°C for the air temperature during the ride.

°C

Known minimum pressure:

Enter a psi floor or leave 0 to use the model's tire-width floor.

psi

Known maximum pressure:

Enter the lowest safe psi ceiling from tire/rim markings, or 0 for none.

psi

#	Wheel	Load	Pump	On-road	Ride window	Safe ride	Margin	Patch	Copy
{{ row.index }}	{{ row.wheel }} {{ row.note }}	{{ row.loadKgDisplay }} {{ row.loadLbDisplay }}	{{ row.pumpPsiDisplay }} {{ row.pumpBarDisplay }}	{{ row.projectedRidePsiDisplay }} {{ row.temperatureDeltaDisplay }}	{{ row.rideBandPsiDisplay }} {{ row.rideBandBarDisplay }}	{{ row.safeRideDisplay }} {{ row.safeRideBarDisplay }}	{{ row.marginDisplay }} {{ row.ceilingDisplay }}	{{ row.patchDisplay }} {{ row.patchLengthDisplay }}

Section	Item	Cue	Detail	Copy
Wheel tuning	{{ row.wheel }}	{{ row.header }}	{{ row.startText }} {{ row.lowerText }} {{ row.upperText }} {{ row.watchText }}
Setup check	{{ check.title }}	{{ check.short }}	{{ check.message }}

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Bicycle tire pressure is a balance between load support, rolling feel, casing protection, grip, rim safety, and comfort. The right target changes with rider and bike weight, tire width, inner rim width, surface, tire casing, tube or tubeless setup, inserts, weather grip, and the temperature difference between inflation and riding.

Front and rear tires rarely need identical pressure because the wheels carry different shares of the system weight. A rear tire often carries more load, while the front tire may need a little more grip and steering feel. Cold pump pressure and riding pressure can also differ when a tire is inflated in a warm room, a cold garage, or a different outdoor temperature than the ride itself.

Front and rear bicycle tire pressure targets as separate load-based ranges.

Pressure estimates are starting points for testing, not permission to ignore tire or rim limits. Tires vary by casing, measured width, bead design, rim compatibility, and manufacturer pressure markings. If a target is close to a tire, rim, or wheel-system maximum, follow the lower equipment limit and consider more tire volume.

A pressure estimate is most useful when it describes the actual setup: measured tire width rather than label width, real system weight with gear, actual rim internal width, and the surface you are about to ride.

How to Use This Tool:

Enter the setup as it will be ridden, then check the front and rear targets against your equipment limits.

Choose Riding category. This sets the baseline pressure profile for road race, endurance, gravel, mountain, commuter, bikepacking, downhill, or indoor use.
Enter System weight and the matching unit. Include the rider, bike, bottles, bags, tools, clothing, and any cargo that affects tire load.
Use the measured casing width in Measured tire width. A 30 mm labeled tire can measure wider or narrower depending on the rim.
Enter Rim internal width and choose Wheel size. The calculator checks rim-to-tire fit and applies a rim-width pressure adjustment.
Select Surface, Ride feel, and Setup. Rougher surfaces, wet grip, tubeless setup, supple casings, and inserts can all move the target.
Open Advanced for Extra carried weight, Casing, Weather grip, manual Load split, Tire inserts, temperatures, and known minimum or maximum pressure limits.
Review Wheel Targets, then use Tune Notes to see whether weight split, profile match, rim match, temperature, or equipment limits need attention.

If the result feels too harsh, reduce pressure in small steps within the ride window. If the tire squirms, bottoms on the rim, burps, or shows casing damage, move pressure up or choose a larger tire, stronger casing, or more suitable rim and tire combination.

Interpreting Results:

Cold pump is the pressure to set before the ride at the entered inflation temperature. On-road is the pressure expected at ride temperature. These can differ because gas pressure changes with temperature. Ride window gives a practical adjustment band around the target.

The front and rear targets usually differ. Rear pressure is often higher because the rear wheel carries more load, while the front may need more grip and steering feel. Manual Load split should be used when the bike geometry, cargo placement, or riding position is not represented well by the automatic profile.

Load shows how much weight the wheel is modeled to carry.
Safe ride shows the calculator's internal ride-pressure floor and ceiling after setup factors, not a substitute for manufacturer limits.
Margin shows how much room remains between the projected ride pressure and the modeled safety boundaries.
Patch estimates contact patch area from wheel load and projected ride pressure.
Pressure Load Curves shows how targets move as system weight changes, which is helpful for cargo and bikepacking setups.

Technical Details:

The pressure model starts from load per wheel and measured tire width. Wider tires generally need less pressure for the same load because the air volume and casing support are larger. The selected riding category supplies a profile factor and a default front-load share. Surface, ride feel, tube or tubeless setup, casing, weather grip, rim ratio, inserts, and wheel size then adjust the baseline.

Temperature handling uses absolute pressure rather than gauge pressure alone. Gauge PSI is converted to absolute pressure by adding atmospheric pressure, scaled by the ratio of ride temperature to inflation temperature in kelvin, then converted back to gauge PSI. This is why the Cold pump target can be lower or higher than the expected ride pressure.

Formula Core:

The wheel target begins with wheel load and tire width, then applies the profile and setup multipliers before clamping to modeled safety limits.

{PSI}_{ride} = clamp (\frac{L_{kg} \times 52.5}{W_{mm}} \times F \times C, {PSI}_{min}, {PSI}_{max})

Temperature conversion uses the same gas-law relationship in reverse when cold pump pressure is derived from the target riding pressure.

{PSI}_{to} = (({PSI}_{from} + 14.6959) \times \frac{T_{to} + 273.15}{T_{from} + 273.15}) - 14.6959

Bicycle tire pressure variables
Symbol	Meaning	Where it comes from	Result effect
`L`	Wheel load	System weight, extra carried weight, and front or rear load share.	Higher load raises pressure.
`W`	Measured tire width	The inflated tire width in millimeters.	Wider tires lower pressure for the same load.
`F`	Profile and wheel factor	Riding category and wheel size.	Adapts the baseline for road, gravel, MTB, cargo, or indoor use.
`C`	Combined setup factor	Surface, ride feel, setup, casing, weather, rim ratio, and inserts.	Moves the pressure toward grip, comfort, protection, or firmness.
`clamp`	Modeled safety bounds	Width-based floor and ceiling plus setup adjustments and entered limits.	Prevents the output from leaving the supported pressure band.

Known minimum and maximum pressure fields are applied after temperature conversion. This matters when a sidewall, rim decal, or wheel manual gives a limit in cold pump terms. If both a tire and rim maximum apply, use the lower system limit. The calculator also rejects impossible geometry, such as a rim internal width that is not narrower than the tire.

Bicycle tire pressure validation checks
Check	Boundary	Why it matters
`Measured tire width`	At least `18 mm`	Very narrow or invalid widths break the supported tire model.
`Rim internal width`	At least `15 mm` and less than tire width	Rim-to-tire relationship affects pressure and compatibility.
`Load split`	Manual front share from `38%` to `52%`	Controls how total weight is assigned to front and rear targets.
`Inflation temp` and `Ride temp`	`-20 C` to `50 C`	Bounds the temperature correction to ordinary cycling conditions.
`Known maximum pressure`	Must be above known minimum when both are entered	Equipment limits need a valid pressure range before clamping.

Bicycle tire pressure setup factors
Input	Lower-pressure tendency	Higher-pressure tendency
`Surface`	Broken pavement, gravel, mud, roots, or loose surfaces.	Smooth pavement, trainer use, or high-speed road riding.
`Ride feel`	Comfort or grip priority.	Firm or race-feel priority.
`Setup`	Tubeless setup and inserts can support lower targets.	Butyl tubes and pinch-flat risk tend to need more pressure.
`Casing`	Supple casing.	Reinforced, downhill, or stiff casing when protection is prioritized.
`Weather grip`	Wet or slippery conditions.	Dry conditions with no extra grip reserve.

Worked Examples:

Endurance road setup

An 82 kg system weight, 30 mm measured tire, 21 mm internal rim, endurance category, 700C wheel, normal pavement, balanced feel, and tubeless setup gives separate front and rear targets around the mid-pressure road range. The rear target is higher because the rear wheel carries more load.

Fast gravel with wet grip

A wider gravel tire with a tubeless setup, rougher surface, and wet grip reserve will usually move the target lower than a pavement setup with the same rider weight. Use the ride window to test grip and rim-strike margin in small steps rather than making one large change.

Bikepacking with extra cargo

Adding 8 kg of carried weight raises both wheel loads. If most cargo is on a rear rack, use manual Load split to place more load on the rear wheel, then check whether the rear target is near the known maximum pressure or the rim's maximum rating.

FAQ:

Should I use tire label width or measured width?

Measured width is better. Tire casing shape changes with rim internal width, pressure, and model, so the sidewall label can differ from the inflated size.

Why are the front and rear pressures different?

The two wheels normally carry different load shares. The rear wheel often carries more weight, so it often needs more pressure for similar casing support.

Can I exceed the rim or tire maximum if the calculator suggests it?

No. Use the lower maximum from the tire, rim, wheel system, and manufacturer guidance. If the needed pressure is too close to that limit, choose a larger tire or different setup.

Why does temperature change the pump target?

Air pressure changes with absolute temperature. A tire inflated in a cold garage can read differently after warming during a ride, so the calculator separates cold pump pressure from expected ride pressure.

How should I tune after the first ride?

Move in small steps within the ride window. Raise pressure if the tire feels unstable or hits the rim; lower it if the ride is harsh and grip is poor, while staying above the equipment minimum.

Glossary:

System weight: The combined weight of rider, bike, clothing, bottles, tools, bags, and cargo.
Measured tire width: The actual inflated casing width, which may differ from the sidewall label.
Rim internal width: The inside bead-seat width of the rim, used here to adjust fit and pressure behavior.
Cold pump pressure: The gauge pressure to set at the inflation temperature before riding.
Ride window: A practical adjustment range around the modeled target for testing feel, grip, and support.

References:

How To Calculate Tire Pressure, SRAM/Zipp.
Hookless Tire Compatibility Guide, SRAM/Zipp.
Tire Pressure, ENVE Composites.
Tire Compatibility, ENVE Composites.