Skip to main content

Millibar to PSI Converter
↔ Convert psi to mbar instead

Common Conversions

mbar psi
0.01 0.000145
0.1 0.00145
0.25 0.003626
0.5 0.007252
1 0.014504
2 0.029008
5 0.072519
10 0.145038
25 0.362594
50 0.725189
100 1.45
1000 14.504

Why this conversion matters in chemistry

European compressed-air and instrument-line specs run in mbar; US-spec pneumatic actuators, regulators, and pressure gauges read in psi. The factor is 0.014504 psi per mbar — exact through the SI definitions, since 1 psi equals 6894.76 Pa and 1 mbar equals 100 Pa. A 6000 mbar instrument-air supply translates to 87 psi, the value a US-spec control-valve positioner expects on its supply port. Converting between the two is the ordinary step at the boundary between European-built equipment and US-spec piping or controls.

Formula

psi = mbar × 0.014504

Worked Examples

1013.25 mbar = 14.696 psi

Standard atmospheric pressure expressed in both unit systems.

1 mbar = 0.01450 psi

One millibar in psi — useful as a sanity check on a low-pressure measurement.

100 mbar = 1.450 psi

A low-pressure gas-handling spec — about 0.1 bar of overpressure.

2000 mbar = 29.008 psi

About 2 atm — the kind of moderate pressurization a small reactor or autoclave might run at.

Frequently Asked Questions

How do I convert millibar to psi?
Multiply by 0.014504. So 1013.25 mbar becomes 14.696 psi — one standard atmosphere expressed in both unit conventions.
When does this conversion come up?
Connecting European lab vacuum systems (which read in mbar) to US-spec compressed-gas lines, regulators, or pneumatic instrumentation calibrated in psi. The translation comes up most often during scale-up to a pilot plant where equipment vendors come from both markets.
What's 1 mbar in psi?
About 0.0145 psi — a very small pressure in psi terms, which is part of why mbar is the unit of choice for measuring small pressure differences and vacuum levels in chemistry labs.