• inHg   hPa
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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 hectopascal (hPa) is a commonly used unit for measuring atmospheric pressure, especially in meteorology. One hPa is equivalent to 100 pascals, making it a preferred measurement over pascals due to the convenient scale. Interestingly, 1 hPa is also equivalent to 1 millibar, a unit that was widely used before the adoption of the hectopascal. This equivalence makes it easy for transitioning instruments and readings in weather maps and reports.

Hectopascals play a crucial role in understanding atmospheric conditions, such as weather forecasting and studying phenomena like hurricanes or cyclones. Typically, sea-level pressure is around 1013 hPa, and deviations from this can indicate changing weather patterns, with lower pressures often associated with storm systems. This connection makes the hPa unit vital for predicting and understanding weather events globally.

> Inches of mercury to Hectopascals Conversion Table

Inches of mercury Hectopascals
0 inHg 0 hPa
1 inHg 33.86389 hPa
2 inHg 67.72778 hPa
3 inHg 101.59167 hPa
4 inHg 135.45556 hPa
5 inHg 169.31945 hPa
6 inHg 203.18334 hPa
7 inHg 237.04723 hPa
8 inHg 270.91112 hPa
9 inHg 304.77501 hPa
10 inHg 338.6389 hPa
11 inHg 372.50278 hPa
12 inHg 406.36667 hPa
13 inHg 440.23056 hPa
14 inHg 474.09445 hPa
15 inHg 507.95834 hPa
16 inHg 541.82223 hPa
17 inHg 575.68612 hPa
18 inHg 609.55001 hPa
19 inHg 643.4139 hPa
20 inHg 677.27779 hPa
21 inHg 711.14168 hPa
22 inHg 745.00557 hPa
23 inHg 778.86946 hPa
24 inHg 812.73335 hPa
25 inHg 846.59724 hPa
26 inHg 880.46113 hPa
27 inHg 914.32502 hPa
28 inHg 948.18891 hPa
29 inHg 982.0528 hPa
30 inHg 1015.91669 hPa
31 inHg 1049.78058 hPa
32 inHg 1083.64447 hPa
33 inHg 1117.50835 hPa
34 inHg 1151.37224 hPa
35 inHg 1185.23613 hPa
36 inHg 1219.10002 hPa
37 inHg 1252.96391 hPa
38 inHg 1286.8278 hPa
39 inHg 1320.69169 hPa
40 inHg 1354.55558 hPa
41 inHg 1388.41947 hPa
42 inHg 1422.28336 hPa
43 inHg 1456.14725 hPa
44 inHg 1490.01114 hPa
45 inHg 1523.87503 hPa
46 inHg 1557.73892 hPa
47 inHg 1591.60281 hPa
48 inHg 1625.4667 hPa
49 inHg 1659.33059 hPa
50 inHg 1693.19448 hPa
51 inHg 1727.05837 hPa
52 inHg 1760.92226 hPa
53 inHg 1794.78615 hPa
54 inHg 1828.65003 hPa
55 inHg 1862.51392 hPa
56 inHg 1896.37781 hPa
57 inHg 1930.2417 hPa
58 inHg 1964.10559 hPa
59 inHg 1997.96948 hPa
60 inHg 2031.83337 hPa
61 inHg 2065.69726 hPa
62 inHg 2099.56115 hPa
63 inHg 2133.42504 hPa
64 inHg 2167.28893 hPa
65 inHg 2201.15282 hPa
66 inHg 2235.01671 hPa
67 inHg 2268.8806 hPa
68 inHg 2302.74449 hPa
69 inHg 2336.60838 hPa
70 inHg 2370.47227 hPa
71 inHg 2404.33616 hPa
72 inHg 2438.20005 hPa
73 inHg 2472.06394 hPa
74 inHg 2505.92783 hPa
75 inHg 2539.79171 hPa
76 inHg 2573.6556 hPa
77 inHg 2607.51949 hPa
78 inHg 2641.38338 hPa
79 inHg 2675.24727 hPa
80 inHg 2709.11116 hPa
81 inHg 2742.97505 hPa
82 inHg 2776.83894 hPa
83 inHg 2810.70283 hPa
84 inHg 2844.56672 hPa
85 inHg 2878.43061 hPa
86 inHg 2912.2945 hPa
87 inHg 2946.15839 hPa
88 inHg 2980.02228 hPa
89 inHg 3013.88617 hPa
90 inHg 3047.75006 hPa
91 inHg 3081.61395 hPa
92 inHg 3115.47784 hPa
93 inHg 3149.34173 hPa
94 inHg 3183.20562 hPa
95 inHg 3217.06951 hPa
96 inHg 3250.9334 hPa
97 inHg 3284.79728 hPa
98 inHg 3318.66117 hPa
99 inHg 3352.52506 hPa
100 inHg 3386.38895 hPa