The “inch of mercury” (inHg) is a unit of pressure commonly used in aviation, meteorology, and refrigeration. It originates from the barometric pressure measurement practice using a column of mercury. This unit became a staple due to its early adoption in weather forecasting and its accurate and consistent measurements. An interesting fact is that an inch of mercury is approximately equal to 33.86 millibars or 3386 Pascals, but what truly distinguishes it is its historical significance in the development of modern atmospheric science.

In the 17th century, Evangelista Torricelli, a student of Galileo, first discovered that atmospheric pressure could sustain a column of mercury, laying the groundwork for this unit. His invention, the barometer, revolutionized how we understand and predict weather, marking the inch of mercury as more than just a unit—it’s a nod to the evolution of scientific inquiry and practice.

Did you know?

The “bar” is a metric unit of pressure, commonly used in meteorology to describe atmospheric pressure — one bar is approximately equal to the atmospheric pressure on Earth at sea level. Interestingly, the term “bar” originates from the Greek word “baros,” meaning weight. This unit is not only practical for forecasting weather but also critical in various scientific fields, such as oceanography and engineering, where accurate pressure measurements are crucial.

A fascinating aspect of the bar is its application in scuba diving. Divers often use bar to read their submersible pressure gauges to monitor air consumption. Moreover, understanding bar pressure changes is essential in deep-sea diving to avoid decompression sickness, a condition caused by rapid changes in pressure. Thus, the bar is a pivotal unit in both scientific and everyday contexts.

Inches of mercury

Bar

0 inHg

0 bar

1 inHg

0.0338639 bar

2 inHg

0.0677278 bar

3 inHg

0.101592 bar

4 inHg

0.135456 bar

5 inHg

0.169319 bar

6 inHg

0.203183 bar

7 inHg

0.237047 bar

8 inHg

0.270911 bar

9 inHg

0.304775 bar

10 inHg

0.338639 bar

11 inHg

0.372503 bar

12 inHg

0.406367 bar

13 inHg

0.440231 bar

14 inHg

0.474094 bar

15 inHg

0.507958 bar

16 inHg

0.541822 bar

17 inHg

0.575686 bar

18 inHg

0.60955 bar

19 inHg

0.643414 bar

20 inHg

0.677278 bar

21 inHg

0.711142 bar

22 inHg

0.745006 bar

23 inHg

0.778869 bar

24 inHg

0.812733 bar

25 inHg

0.846597 bar

26 inHg

0.880461 bar

27 inHg

0.914325 bar

28 inHg

0.948189 bar

29 inHg

0.982053 bar

30 inHg

1.01592 bar

31 inHg

1.04978 bar

32 inHg

1.08364 bar

33 inHg

1.11751 bar

34 inHg

1.15137 bar

35 inHg

1.18524 bar

36 inHg

1.2191 bar

37 inHg

1.25296 bar

38 inHg

1.28683 bar

39 inHg

1.32069 bar

40 inHg

1.35456 bar

41 inHg

1.38842 bar

42 inHg

1.42228 bar

43 inHg

1.45615 bar

44 inHg

1.49001 bar

45 inHg

1.52388 bar

46 inHg

1.55774 bar

47 inHg

1.5916 bar

48 inHg

1.62547 bar

49 inHg

1.65933 bar

50 inHg

1.69319 bar

51 inHg

1.72706 bar

52 inHg

1.76092 bar

53 inHg

1.79479 bar

54 inHg

1.82865 bar

55 inHg

1.86251 bar

56 inHg

1.89638 bar

57 inHg

1.93024 bar

58 inHg

1.96411 bar

59 inHg

1.99797 bar

60 inHg

2.03183 bar

61 inHg

2.0657 bar

62 inHg

2.09956 bar

63 inHg

2.13343 bar

64 inHg

2.16729 bar

65 inHg

2.20115 bar

66 inHg

2.23502 bar

67 inHg

2.26888 bar

68 inHg

2.30274 bar

69 inHg

2.33661 bar

70 inHg

2.37047 bar

71 inHg

2.40434 bar

72 inHg

2.4382 bar

73 inHg

2.47206 bar

74 inHg

2.50593 bar

75 inHg

2.53979 bar

76 inHg

2.57366 bar

77 inHg

2.60752 bar

78 inHg

2.64138 bar

79 inHg

2.67525 bar

80 inHg

2.70911 bar

81 inHg

2.74298 bar

82 inHg

2.77684 bar

83 inHg

2.8107 bar

84 inHg

2.84457 bar

85 inHg

2.87843 bar

86 inHg

2.91229 bar

87 inHg

2.94616 bar

88 inHg

2.98002 bar

89 inHg

3.01389 bar

90 inHg

3.04775 bar

91 inHg

3.08161 bar

92 inHg

3.11548 bar

93 inHg

3.14934 bar

94 inHg

3.18321 bar

95 inHg

3.21707 bar

96 inHg

3.25093 bar

97 inHg

3.2848 bar

98 inHg

3.31866 bar

99 inHg

3.35253 bar

100 inHg

3.38639 bar

Conversion

Inches of mercury to Pascals

Go to converter

Inches of mercury to Kilopascals

Go to converter

Inches of mercury to Megapascals

Go to converter

Inches of mercury to Hectopascals

Go to converter

Inches of mercury to Millibar

Go to converter

Inches of mercury to Torr

Go to converter

Inches of mercury to Meters of water @ 4°C

Go to converter

Inches of mercury to Millimeters of mercury

Go to converter

Inches of mercury to Pounds per square inch

Go to converter

Inches of mercury to Kilopound per square inch

Go to converter

Inches of mercury to Bar Conversion

Did you know?

> Inches of mercury to Bar Conversion Table

> Other Conversions

:: Pressure Units

Did you know? Expand

> Inches of mercury to Bar Conversion Table

> Other Conversions

:: Pressure Units

:: Spread the Word

Did you know?