inHg to mmHg Converter

Pressure · unit-converter

Convert inHg to mmHg with a fixed input and output unit, step-by-step formula line, and reference tables. All calculations bridge through pascal with fixed definitions (standard atmosphere = 101,325 Pa; torr and mmHg = atm/760; plus industrial/manometer units like kgf/cm², inHg, inH2O, and mmH2O).

About inHg

Inches of mercury (inHg) is used in aviation altimetry and vacuum readings in some US contexts.

About mmHg

Millimeters of mercury (mmHg) is common in medicine (e.g. blood pressure). Here it uses the same Pa per unit as torr (133.32236842105263 Pa).

How to convert inch of mercury (inhg) to millimeter of mercury (mmhg)

1 inhg equals 25.39999999996447 mmhg in this tool (via pascal):

1 inhg = (3386.38815789 Pa ÷ 133.32236842105263 Pa) mmhg = 25.39999999996447 mmhg

Each inhg carries 3386.38815789 Pa and each mmhg 133.32236842105263 Pa, so one inhg equals 3386.38815789 ÷ 133.32236842105263 mmhg.

Let p(inhg) be pressure in inHg (inhg), and p(mmhg) in mmHg (mmhg). Then:

p(mmhg) = p(inhg) × (3386.38815789 / 133.32236842105263)

Equivalently, divide by how many inhg fit into one mmhg (Pa per mmhg divided by Pa per inhg):

p(mmhg) = p(inhg) ÷ 0.03937007874021255

Examples

Example #1: Convert 1 inhg to mmhg

1 inhg = 1 inhg × (3386.38815789/133.32236842105263) mmhg = 25.4 mmhg

1 inhg = 1 inhg ÷ 0.03937007874021255 = 25.4 mmhg

1 inhg × (3,386.38815789/133.32236842105263) = 25.400000 mmhg

Example #2: Convert 10 inhg to mmhg

10 inhg = 10 inhg × (3386.38815789/133.32236842105263) mmhg = 254 mmhg

10 inhg = 10 inhg ÷ 0.03937007874021255 = 254 mmhg

10 inhg × (3,386.38815789/133.32236842105263) = 254.000000 mmhg

Summary

To convert inHg to mmHg, multiply the value in inhg by (3386.38815789 Pa per inhg) / (133.32236842105263 Pa per mmhg). Equivalently: value_mmhg = value_inhg × (3386.38815789 / 133.32236842105263). Numerically, 1 inhg equals 25.39999999996447 mmhg.

Relationship context

Both inHg and mmHg are converted by fixed multiples of the pascal. Multiplying by (Pa per inhg) ÷ (Pa per mmhg) gives the same result as passing through pascal, keeping bar, atm, PSI, kPa, hPa, torr, and mmHg consistent on the hub.

Conversion tables

inHg (inhg)mmHg (mmhg)
0.12.54
125.4
250.7999999999
376.1999999999
4101.6
5127
6152.4
7177.8
8203.2
9228.6
inHg (inhg)mmHg (mmhg)
10254
20507.999999999
30761.999999999
401,016
501,270
601,524
701,778
802,032
902,286
1002,540