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Kilopascal to Inches of Mercury Converter
↔ Convert inHg to kPa instead

Common Conversions

kPa inHg
1 0.2953
5 1.4765
10 2.953
25 7.383
50 14.765
100 29.53
101.325 29.921
200 59.06
500 147.65
1000 295.3
5000 1476.5
10000 2953

Why this conversion matters in chemistry

Modern process equipment carries kPa pressure ratings; older US-built field instruments and US meteorological data display in inches of mercury. A 101 kPa relief-valve setting is 29.83 inHg on a legacy Bourdon gauge. The constant of 0.2953 inHg per kPa falls cleanly out of 29.92 inHg per atmosphere divided by 101.325 kPa per atmosphere. In practice you reach for it when an SI-spec process datasheet meets a US-spec gauge or a barometric report calibrated against a mercury column.

Formula

inHg = kPa × 0.295300

Worked Examples

101.325 kPa = 29.921 inHg

Standard atmospheric pressure expressed in both unit systems.

1 kPa = 0.2953 inHg

The factor itself — a useful quick reference when scanning a kPa value.

100 kPa = 29.530 inHg

Exactly 1 bar — the IUPAC reference pressure for tabulated thermodynamic data, expressed in inHg.

50 kPa = 14.765 inHg

About half an atmosphere — the kind of reduced pressure a vacuum operation might hold.

Frequently Asked Questions

How do I convert kPa to inches of mercury?
Multiply by 0.2953. So 101.325 kPa becomes 29.921 inHg — the standard atmospheric pressure expressed in both unit systems.
Where is inHg still used?
US meteorological reports, aviation altimeter settings, HVAC engineering, and some older US industrial chemistry references. Almost all modern scientific work uses kPa or bar.
How does inHg relate to other pressure units?
1 inHg equals 3.38639 kPa, 25.4 mmHg, or 0.033421 atm. The unit is defined by the height of a mercury column expressed in inches, and the factor falls out cleanly through the inch and millimeter definitions.