Tires and Wheels
Altitude Tire Pressure Correction Calculator
Estimate gauge-pressure change from atmospheric pressure and temperature differences. Atmospheric pressure depends on weather as well as elevation.
Values used in the formula
Record physical measurements under repeatable conditions whenever possible.
Scope of the calculation
Estimate gauge-pressure change from atmospheric pressure and temperature differences — a calculated clearance or dimension still requires a physical check on the vehicle.
Atmospheric pressure depends on weather as well as elevation — that condition defines when estimated new gauge pressure is comparable with another result.
Gauge pressure at start is defined here as tire pressure relative to starting atmospheric pressure — keeping that definition intact requires you to record gauge type, temperature, and whether the value is absolute or relative pressure.
For Starting atmospheric pressure, use the quantity described as absolute pressure at the starting elevation — in the vehicle record, record gauge type, temperature, and whether the value is absolute or relative pressure.
Document New atmospheric pressure as absolute pressure at the new elevation — this means you should record gauge type, temperature, and whether the value is absolute or relative pressure.
Starting tire temperature. Temperature at the first reading — for this measurement, use a measurement or specification from the exact component and operating condition being evaluated.
New tire temperature: Temperature at the new elevation — a compatible entry should use a measurement or specification from the exact component and operating condition being evaluated.
Collecting the data in practice
Measure the installed component and the vehicle reference points rather than relying only on a catalog dimension — this workflow must also account for the fact that atmospheric pressure depends on weather as well as elevation.
- Record Gauge pressure at start as tire pressure relative to starting atmospheric pressure — record gauge type, temperature, and whether the value is absolute or relative pressure.
- Record Starting atmospheric pressure as absolute pressure at the starting elevation — record gauge type, temperature, and whether the value is absolute or relative pressure.
- Record New atmospheric pressure as absolute pressure at the new elevation — record gauge type, temperature, and whether the value is absolute or relative pressure.
- Record Starting tire temperature as temperature at the first reading — use a measurement or specification from the exact component and operating condition being evaluated.
Formula used on this page
In “new gauge pressure = temperature-adjusted absolute tire pressure − new atmospheric pressure,” the equation links gauge pressure at start, starting atmospheric pressure, and new atmospheric pressure to estimated new gauge pressure.
No term beyond gauge pressure at start, starting atmospheric pressure, new atmospheric pressure, starting tire temperature, and new tire temperature is introduced in “new gauge pressure = temperature-adjusted absolute tire pressure − new atmospheric pressure.”
Limits of this calculation
Suspension travel, steering angle, tire growth, body tolerances, and alignment can reveal interference that a static dimension misses — for starting atmospheric pressure, the page specifically expects absolute pressure at the starting elevation.
Keep this result separate from the task to estimate tread wear per 1,000 miles and remaining mileage at the same rate, which is available in the Tire Tread Wear Rate.
Example using the displayed inputs
The sample vehicle case enters Gauge pressure at start = 35 psi, Starting atmospheric pressure = 14.7 psi, New atmospheric pressure = 12.2 psi, Starting tire temperature = 70 °F, and New tire temperature = 70 °F.
That specific combination leads to Estimated new gauge pressure = 37.5 psi and Gauge-pressure change = 2.5 psi.
Interpreting the headline value
Estimated new gauge pressure answers “Estimate gauge-pressure change from atmospheric pressure and temperature differences.” The additional display, Gauge-pressure change, is a different view of the same entered measurements.
Use an accurate gauge and follow placard guidance — when that condition changes, compare separate calculator runs instead of blending the inputs.
Because atmospheric pressure depends on weather as well as elevation, a disagreement between estimated new gauge pressure and an outside reference should trigger a review of gauge pressure at start and new tire temperature.
Questions about the formula and inputs
What measurement source fits Gauge pressure at start when it represents tire pressure relative to starting atmospheric pressure?
Because gauge pressure at start represents tire pressure relative to starting atmospheric pressure, use a source tied to the exact vehicle, component, and operating period described by the other fields.
How does the warning “Atmospheric pressure depends on weather as well as elevation” affect Estimated new gauge pressure?
The condition “Atmospheric pressure depends on weather as well as elevation” is not corrected automatically by the numeric inputs, so create a separate altitude tire pressure correction case when it changes.
What assumption is expressed by “new gauge pressure = temperature-adjusted absolute tire pressure − new atmospheric pressure”?
In “new gauge pressure = temperature-adjusted absolute tire pressure − new atmospheric pressure,” gauge pressure at start and starting atmospheric pressure are treated as parts of one vehicle case.
How narrowly is Starting atmospheric pressure defined by “Absolute pressure at the starting elevation”?
The definition “Absolute pressure at the starting elevation” excludes a similarly named rating or a measurement taken at another reference point.