How do I calculate tire pressure for a heavier load or towing?

Weigh each axle (or estimate axle weight), divide by the number of tires on that axle, then scale sidewall max PSI by (load per tire ÷ sidewall max load). Cap at max sidewall PSI and never ignore the door placard for unloaded daily driving.

Should I use the door placard or the sidewall max PSI?

The door placard is the cold pressure for the stock tire and typical curb/load. Sidewall max PSI is the tire’s absolute ceiling at its max load rating — not a everyday target. This calculator estimates upward from placard when axle load rises, without exceeding sidewall max.

Does temperature change tire pressure?

Roughly 1 psi for every 10°F. Check and set pressure cold (before driving). The temperature section only estimates what a warm gauge may read relative to a cold reference — it is not a substitute for a cold set.

Is linear load scaling as accurate as a tire load-inflation table?

No. Linear scaling is a common DIY estimate. Light truck (LT) and trailer (ST) tires often publish manufacturer load-inflation tables that are more accurate for towing. Prefer those tables when you have them.

Can I run lower pressure than the placard when empty?

This tool floors estimates at about 80% of placard so empty-axle math does not suggest unsafe soft tires. For comfort or off-road air-down, follow the tire maker and vehicle guidance — not an empty-scale formula alone.

Tire Pressure Calculator

Estimate cold front and rear inflation from axle weight and sidewall ratings — for loaded trips and towing, not just the door placard.

Scale axle weight against sidewall max load to estimate cold inflation for each end.

Load presets

Rough axle-weight starting points — replace with scale weights when you can.

Tire sidewall + placard

Same tires front & rear

Max load / tire (lb)Sidewall “MAX LOAD”

Max cold PSISidewall max inflation

Door placard PSICold OEM recommendation

Front axle

Axle weight (lb)

Tires on axle

Inflation bay

Front

Within tire rating

Cold inflate to

psi · 28 psi · 1.93 bar · 193 kPa

Load / tire
1400
lb
Capacity
63%
of max
vs placard
-7
psi

Rear axle

Axle weight (lb)

Tires on axle

Inflation bay

Rear

Within tire rating

Cold inflate to

31.9

psi · 31.9 psi · 2.2 bar · 220 kPa

Load / tire
1600
lb
Capacity
73%
of max
vs placard
-3.1
psi

Temperature correction · ~1 psi / 10°F

Reference cold (°F)

Ambient now (°F)

Front @ ambient

28 psi

Rear @ ambient

31.9 psi

Still set pressure cold when you can. The ambient line only estimates what a warm gauge may read if the cold target was set at the reference temperature (Δ 0°F).

Estimate only — sidewall load tables and the vehicle placard win.

This uses linear load scaling capped at max sidewall PSI. For LT/ST towing, prefer the tire maker’s load-inflation table when you have it. Never exceed sidewall max pressure.

Tire pressure for load, towing, and temperature

Door placard PSI is for stock tires at typical load — not a blank check at max sidewall.
Heavier axles (passengers, cargo, tongue weight) need more cold pressure up to the tire’s max.
Set pressure cold; heat from driving or sun raises gauge readings by about 1 psi per 10°F.

Underinflation under load cooks the shoulder, hurts fuel economy, and can leave the tire overloaded relative to its rating. Overinflation for an empty daily drive rides harsh and can cut contact patch. This free tire pressure calculator estimates cold inflation from axle weight, tires per axle, and the sidewall max-load / max-PSI pair — the same linear load-scaling approach many DIY and towing worksheets use.

Enter max load and max cold PSI from the sidewall, the OEM placard number from the door jamb, and front/rear axle weights (scale weights beat guesses). The inflation bay shows a recommended cold target, load percent of the tire rating, and how far that sits above or below the placard. Dual-rear trucks can set four tires on the rear axle.

Treat the result as an estimate. Prefer the tire manufacturer’s load-inflation table for LT and ST towing duty, never exceed sidewall max pressure, and re-check cold after big temperature swings. Pair this with the pressure unit converter when your gauge and placard disagree on units.

How to use the tire pressure calculator

Enter sidewall max load and max cold PSI. Read “MAX LOAD” and max inflation from the tire sidewall; enter the door-jamb placard PSI as well.
Set front and rear axle weights. Use scale weights when possible. Pick a load preset only as a starting point for empty, loaded, or towing.
Read cold inflate targets per axle. Inflate to the recommended cold PSI (front and rear may differ). Optionally check the ambient estimate if you only have a warm gauge reading.