Tire Pressure Calculator
The only single tool that calculates precise cold-inflation PSI for every vehicle type — cars, SUVs, trucks, motorcycles — including temperature corrections and altitude offsets. For bicycle-specific PSI, use the bike PSI calculator for weight-adjusted front and rear values.
Quick Reference — Vehicle Tire Pressure
Pre-calculated results for common setups — use the calculator below for your exact inputs.
| Vehicle & Setup | Front PSI | Rear PSI |
|---|---|---|
| Compact car — 205/55R16, standard load, cold inflation | 32 | 32 |
| Mid-size SUV — 235/60R18, full passenger load | 36 | 38 |
| Pickup truck — 265/70R17, empty bed | 35 | 35 |
| Pickup truck — 265/70R17, towing trailer | 35 | 65 |
Always check your vehicle's door placard. PSI values are cold (before driving).
Enter the outside temperature where you are inflating. The calculator uses the Ideal Gas Law to predict hot PSI after driving — showing you exactly why you should never release air from a warm tire.
Current outside temp
At high altitude, atmospheric pressure is lower — your gauge reads approximately 0.5 PSI higher per 1,000 ft than at sea level for the same absolute tire pressure.
Feet above sea level
Typical Scenarios
Why Cold Inflation and Load Change Everything
The warm-tire trap — the most common tire pressure mistake
A family SUV with a door-placard recommendation of 35 PSI cold will read 39 to 41 PSI on a gauge after a 30-minute highway drive — not because the tire is over-inflated, but because driving heat has expanded the air inside. Releasing air to bring a hot tire down to 35 PSI will result in dangerous under-inflation once the tire cools back to ambient temperature.
Loaded SUV — when door-placard pressure is not enough
A 4,200 lbs mid-size SUV with 235/60R18 tires (Load Index 103, rated at 1,929 lbs per tire) carrying a full passenger load of 800 lbs requires 38 PSI cold rather than the standard 35 PSI empty-vehicle recommendation, to maintain safe load-carrying capacity. The same vehicle inflated to 35 PSI with a full family aboard will run the tires hotter and wear the inner shoulder prematurely.
Motorcycle cold-weather inflation — the 2-3 PSI offset rule
A motorcycle rider inflating tires at 40°F (4°C) for a ride in 85°F (29°C) heat must account for a 4 to 5 PSI pressure gain during the ride. The correct cold inflation pressure is 2 to 3 PSI lower than the factory specification to prevent over-inflation at operating temperature — the opposite error from the warm-tire trap above.
Quick Reference
Tire Pressure by Vehicle Type
Standard cold inflation · typical tire sizes · all values in PSI
| Vehicle Type | Typical Tire Size | Standard PSI | Loaded PSI | Notes |
|---|---|---|---|---|
| Compact Car | 205/55R16 | 32 PSI | 35 PSI | Check door placard for OEM spec |
| Mid-Size Sedan | 215/60R16 | 33 PSI | 36 PSI | Front/rear may differ by 1–2 PSI |
| Full-Size SUV | 265/65R18 | 36 PSI | 40 PSI | Check B-pillar placard, not tire sidewall |
| Pickup Truck (Empty) | 265/70R17 | 35 PSI | 55 PSI | Rear PSI increases dramatically when loaded |
| Pickup Truck (Towing) | 265/70R17 | 35 PSI | 65 PSI | Always inflate to tow rating before hitching |
| Motorcycle (Street) | 120/70ZR17 F / 180/55ZR17 R | 36 F / 42 R | 38 F / 46 R | Solo vs. two-up significantly changes rear PSI |
| Motorcycle (Sport/Track) | 120/70ZR17 F / 180/55ZR17 R | 33 F / 23 R | N/A | Cold track inflation — rises to target at operating temp |
| Road Bicycle | 700×28mm | 85 F / 90 R | N/A | See bike PSI calculator for weight-adjusted values |
Cold inflation only — check after 3 hours at rest. Always verify against your vehicle's door placard or owner's manual. Motorcycle track values are cold targets only.
Step-by-Step
How to Use This Calculator
- 1
Select your vehicle type
Choose from Car, SUV, Pickup Truck, Van / Minivan, Motorcycle (Street), or Motorcycle (Sport/Track). Each vehicle type applies a completely different pressure model — a pickup truck's towing rear PSI (65 PSI) and a sport motorcycle's cold track inflation (23 PSI rear) have nothing in common.
- 2
Select vehicle load level
Choose Empty, Partial Load, Full Load, or Towing (pickup trucks only). For motorcycles, choose Solo or Two-Up. This is the most important variable for trucks — the difference between an empty and fully loaded pickup rear tire can be 20 to 30 PSI.
- 3
Enter ambient temperature (optional)
Enter the outdoor temperature where you are inflating. The calculator applies the Ideal Gas Law to predict what your gauge will read after 30 minutes of driving. This is the most dangerous knowledge gap in tire maintenance — millions of drivers release air from warm tires that appear over-inflated, causing under-inflation once the tire cools.
- 4
Enter altitude (optional)
If you are inflating at significantly different altitude than sea level — for example, at a mountain trailhead or high-altitude city — enter your elevation in feet. At 5,000 ft, atmospheric pressure is lower and your gauge reads approximately 2.5 PSI higher than at sea level for the same absolute tire pressure.
- 5
Click Calculate and review your results
The tool outputs separate front and rear cold inflation PSI plus the equivalent in bar. If you entered temperature, it also shows the predicted hot PSI after driving — confirming the correct response is to keep that pressure and not release air. For motorcycle track users, the result includes the target operating temperature pressure your tires should reach during the warm-up lap.
Methodology
How Tire Pressure Is Calculated
Temperature correction — Ideal Gas Law
P2 = (P1 + 14.7) × (T2 + 459.67) ÷ (T1 + 459.67) − 14.7
- P1: Gauge pressure at cold inflation temperature (PSI) — what you set on your gauge.
- P2: Predicted gauge pressure at operating temperature — what your gauge reads after driving.
- T1: Cold ambient temperature in °F at the point of inflation.
- T2: Estimated operating temperature in °F (typically ambient +40°F for cars; +50°F for motorcycles).
- +14.7 / −14.7: Atmospheric pressure constant to convert between gauge PSI and absolute PSIA. Omitting this step is the error in the common "1 PSI per 10°F" rule of thumb.
Altitude gauge correction
Gauge correction = 0.5 PSI × (Elevation in feet ÷ 1,000)
At 5,000 ft, your gauge reads approximately 2.5 PSI higher than at sea level for the same absolute tire pressure.
Worked example — loaded SUV, cold morning
4,200 lbs SUV + 800 lbs passengers = 5,000 lbs total · 235/60R18 · Load Index 103 · inflating at 35°F
Load per tire: 5,000 lbs ÷ 4 = 1,250 lbs
LI 103 rated: 1,929 lbs at max pressure
Adjusted PSI: 35 × (1,250 ÷ 1,929) × factor = 38 PSI cold
Temperature check (IGL):
P2 = (38 + 14.7) × (75 + 459.67) ÷ (35 + 459.67) − 14.7
= 52.7 × 534.67 ÷ 494.67 − 14.7 = 42.3 PSI hot
Safe — within normal operating range. Do not release air.
FAQ