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Convert Inches of mercury to Megapascals

1 inch of mercury is 0.003386 MPa. One inch of mercury is exactly 0.003386389 megapascals.

One inch of mercury is 0.003386389 megapascals. To convert inches of mercury to megapascals, multiply by 0.003386389; to go the other way, divide by 0.003386389 or multiply by 295.2998. The factor is exact rather than rounded: it follows from NIST Special Publication 811. The pressure of a one-inch column of mercury at 0 °C, fixed by convention at 3,386.389 pascals.

Factor checked against the defining standard · How we check

Megapascals
0.003386 MPa
Inches of mercury × 0.003386389
value * 0.0033863890.003 MPa

1 inch of mercury in every pressure unit

UnitValueExact factor
pounds per square inch0.4911541996 psi× 0.491154199634
bars0.03386389 bar× 0.03386389
pascals3,386.389 Pa× 3,386.389
kilopascals3.386389 kPa× 3.386389
megapascals0.003386389 MPa× 0.003386389
atmospheres0.03342106094 atm× 0.0334210609425
torr25.40000632 Torr× 25.4000063163
inches of mercury (as entered)1 inHg

Factors are entered by hand from NIST Special Publication 811 rather than derived from a units library, so the ones that terminate are exact rather than rounded.

How do you convert inches of mercury to megapascals?

  1. 1.Take the measurement in inches of mercury.
  2. 2.Multiply by 0.003386389 — that is how many megapascals fit in one inch of mercury.
  3. 3.To go back the other way, divide by 0.003386389, or multiply by 295.2998.

Worked example: 25 inches of mercury to megapascals

Formula
inHg × 0.003386389 = MPa
Arithmetic
25 × 0.003386389 = 0.08466 MPa
Answer
25 inHg = 0.08466 MPa

The factor is exact, so this figure is exact too — only the display is rounded.

Inches of mercury to megapascals conversion table

Inches of mercuryMegapascals
1 inHg0.003386 MPa
2 inHg0.006773 MPa
3 inHg0.010159 MPa
4 inHg0.013546 MPa
5 inHg0.016932 MPa
6 inHg0.020318 MPa
7 inHg0.023705 MPa
8 inHg0.027091 MPa
9 inHg0.030478 MPa
10 inHg0.033864 MPa
12 inHg0.040637 MPa
15 inHg0.050796 MPa
20 inHg0.067728 MPa
25 inHg0.08466 MPa
50 inHg0.169319 MPa
100 inHg0.338639 MPa
200 inHg0.677278 MPa
300 inHg1.015917 MPa
500 inHg1.693195 MPa
1000 inHg3.386389 MPa
2000 inHg6.772778 MPa
5000 inHg16.931945 MPa
10000 inHg33.86389 MPa

What is an inch of mercury?

The pressure of a one-inch column of mercury at 0 °C, fixed by convention at 3,386.389 pascals. US aviation altimeters and barometers read in it.

What is a megapascal?

A million pascals. Concrete strength and hydraulic ratings are specified here: 30 MPa concrete is about 4,350 psi.

How many megapascals are in an inch of mercury?

One inch of mercury is 0.003386389 megapascals, exactly. Going the other way, one megapascal is 295.2998 inches of mercury. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.

Every pressure unit here

UnitSymbolOne of these is
Pounds per square inchpsi6894.7573 pascal
Barsbar100000 pascal
PascalsPathe base unit
KilopascalskPa1000 pascal
MegapascalsMPa1000000 pascal
Atmospheresatm101325 pascal
TorrTorr133.32237 pascal
Inches of mercuryinHg3386.389 pascal

Source: NIST Special Publication 811 — pound-force is exactly 4.4482216152605 N and the inch exactly 0.0254 m

Questions people actually ask

How many megapascals are in an inch of mercury?
0.003386389. A million pascals. Concrete strength and hydraulic ratings are specified here: 30 MPa concrete is about 4,350 psi.
How do I convert megapascals back to inches of mercury?
Divide by 0.003386389, or multiply by 295.2998 — they are the same operation.

Other pressure conversions

Megapascals to inches of mercury — the same conversion the other way.