Tyre pressure converter
Convert tyre pressure between bar, psi, kPa, kgf/cm² and MPa, with hot-to-cold temperature correction and seasonal pressure-loss estimates.
Runs in your browserEvery computation happens in your browser — your data never leaves this device.
Result
All five units, plus hot-tyre correction and seasonal loss.
Enter a tyre pressure to convert
kPa: 0
What this tool does
- Fill a tyre with a psi gauge when the door label says 2.5 bar — that is 36.26 psi.
- Explain a winter TPMS warning: going from 25 °C to 15 °C drops the pressure by about 3.4%.
- Read an imported manual: 32 psi = 220.6 kPa = 2.206 bar = 2.249 kgf/cm².
Example
Input
100
Output
100 kPa = 1 bar（100 kPa） 千帕 (kPa) = 100 kPa 巴 (bar) = 1 bar 磅力每平方英寸 (psi) = 14.503774 psi 千克力每平方厘米（俗称“公斤”） (kgf/cm²) = 1.019716 kgf/cm² 兆帕 (MPa) = 0.1 MPa 热胎修正（25 °C → 35 °C） = 1.03354 bar / 103.354016 kPa 降温修正（35 °C → 25 °C，如入秋） = 96.754827 kPa 季节掉压估算（25 °C → 15 °C） = 约 3.354016 kPa（0.03354 bar） 温度每变化 10 °C，胎压约变化 3.354%（按等容理想气体估算） 冷热胎换算按理想气体 P₂ = P₁ × T₂ ÷ T₁；实际胎压还受湿度、胎体膨胀与渗漏影响，测量请以冷胎（停车 3 小时以上或行驶不足 2 公里）为准。
2.5 bar = 250 kPa = 36.259434 psi = 2.549291 kgf/cm²; filling to 2.5 bar at 25 °C gives about 2.584 bar at 35 °C.
Frequently asked questions
How much do cold and hot tyres differ?
With P₂ = P₁ × (T₂ + 273.15) ÷ (T₁ + 273.15), pressure changes about 3.4% per 10 °C. Manufacturer placards always specify the cold pressure, measured after three hours of rest or less than 2 km of driving.
Which unit is “a few kilos of pressure”?
In Chinese it usually means bar, sometimes kgf/cm²; they differ by about 2% (1 bar = 1.019716 kgf/cm²). Confirm before inflating.
Should seasonal loss be topped up?
Yes. A 10 °C drop costs about 3.4%, so 2.5 bar becomes 2.416 bar from 25 °C to 15 °C. Recheck and set the cold pressure before winter.
Is the temperature correction exact?
It assumes an ideal gas at constant volume, so it is an estimate: real air holds moisture and the carcass expands. Values print via Number(value.toFixed(6)); trust your gauge for the final number.
Keywords：胎压换算bar 转 psikPa 胎压公斤胎压冷热胎修正季节掉压tire pressurekgf/cm2