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Convert Atmospheres to Megapascals

1 standard atmosphere is 0.101325 MPa. One standard atmosphere is exactly 0.101325 megapascals.

One standard atmosphere is 0.101325 megapascals. To convert atmospheres to megapascals, multiply by 0.101325; to go the other way, divide by 0.101325 or multiply by 9.8692327. The factor is exact rather than rounded: it follows from NIST Special Publication 811.

Factor checked against the defining standard · How we check

Megapascals
0.101325 MPa
Atmospheres × 0.101325
value * 0.1013250.101 MPa

1 standard atmosphere in every pressure unit

UnitValueExact factor
pounds per square inch14.69594878 psi× 14.6959487755
bars1.01325 bar× 1.01325
pascals101,325 Pa× 101,325
kilopascals101.325 kPa× 101.325
megapascals0.101325 MPa× 0.101325
atmospheres (as entered)1 atm
torr760 Torr× 760
inches of mercury29.9212524 inHg× 29.9212524019

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 atmospheres to megapascals?

  1. 1.Take the measurement in atmospheres.
  2. 2.Multiply by 0.101325 — that is how many megapascals fit in one standard atmosphere.
  3. 3.To go back the other way, divide by 0.101325, or multiply by 9.8692327.

Worked example: 25 atmospheres to megapascals

Formula
atm × 0.101325 = MPa
Arithmetic
25 × 0.101325 = 2.533125 MPa
Answer
25 atm = 2.533125 MPa

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

Atmospheres to megapascals conversion table

AtmospheresMegapascals
1 atm0.101325 MPa
2 atm0.20265 MPa
3 atm0.303975 MPa
4 atm0.4053 MPa
5 atm0.506625 MPa
6 atm0.60795 MPa
7 atm0.709275 MPa
8 atm0.8106 MPa
9 atm0.911925 MPa
10 atm1.01325 MPa
12 atm1.2159 MPa
15 atm1.519875 MPa
20 atm2.0265 MPa
25 atm2.533125 MPa
50 atm5.06625 MPa
100 atm10.1325 MPa
200 atm20.265 MPa
300 atm30.3975 MPa
500 atm50.6625 MPa
1000 atm101.325 MPa
2000 atm202.65 MPa
5000 atm506.625 MPa
10000 atm1,013.25 MPa

What is a standard atmosphere?

Exactly 101,325 pascals by definition, not by measurement — it was fixed as a reference, and the real pressure outside your window is never precisely 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 a standard atmosphere?

One standard atmosphere is 0.101325 megapascals, exactly. Going the other way, one megapascal is 9.8692327 atmospheres. 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 a standard atmosphere?
0.101325. 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 atmospheres?
Divide by 0.101325, or multiply by 9.8692327 — they are the same operation.

Other pressure conversions

Megapascals to atmospheres — the same conversion the other way.