40 Pounds per square inch to Bar (40 psi to bar)
40 Pounds per square inch equals 2.7579 Bar. Below is the formula, the worked arithmetic, and what 40 psi typically represents in everyday use.
Formula and worked answer
Formula
bar = psi × 0.0689476
Substituting 40 for psi: 40 × 0.0689476 = 2.7579 bar. The factor 0.0689476 comes from the exact international definition of the Pound per square inch relative to the Bar, so this answer is precise rather than rounded.
What does 40 Pounds per square inch represent?
40 psi (2.76 bar) is a common upper recommended cold-tyre pressure for US-market high-performance summer tyres and a typical reference on American sports-car door-jamb stickers. Converted to metric the figure is 2.76 bar, which European performance-tyre recommendations instead post as 2.7 bar or 2.8 bar on the equivalent metric-spec vehicle. The 0.04 bar gap matters at the track: a US 40-psi summer-tyre recommendation translated naively to "2.8 bar" over-inflates by about 4 kPa, which is enough to shift the cornering balance toward understeer on a track-day setup. Performance-tyre buyers crossing borders confirm the precise 0.06895 bar-per-psi factor before adjusting from the door-jamb sticker.
Values near 40 psi
- 35 psi=2.4132 bar
- 36 psi=2.4821 bar
- 37 psi=2.5511 bar
- 38 psi=2.62 bar
- 39 psi=2.689 bar
- 41 psi=2.8269 bar
- 42 psi=2.8958 bar
- 43 psi=2.9647 bar
- 44 psi=3.0337 bar
- 45 psi=3.1026 bar
psi to bar reference table around 40
| psi | bar |
|---|---|
| 20 psi | 1.379 bar |
| 30 psi | 2.0684 bar |
| 35 psi | 2.4132 bar |
| 39 psi | 2.689 bar |
| 40 psi | 2.7579 bar |
| 41 psi | 2.8269 bar |
| 45 psi | 3.1026 bar |
| 50 psi | 3.4474 bar |
| 60 psi | 4.1369 bar |
| 80 psi | 5.5158 bar |
Convert a different value
Looking for a different number of Pounds per square inch? Use the full psi to bar converter to enter any value, see the worked formula, and read the full background on the Pound per square inch and the Bar. To go the other direction, the bar to psi converter applies the inverse factor and is the page to bookmark if you usually start in Bar.