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Convert Atmospheres to Torr

1 standard atmosphere is 760 Torr. One standard atmosphere is exactly 760 torr.

One standard atmosphere is 760 torr. To convert atmospheres to torr, multiply by 760; to go the other way, divide by 760 or multiply by 0.0013157895. The factor is exact rather than rounded: it follows from NIST Special Publication 811.

Factor checked against the defining standard · How we check

Torr
760 Torr
Atmospheres × 760
value * 760760 Torr

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 torr?

  1. 1.Take the measurement in atmospheres.
  2. 2.Multiply by 760 — that is how many torr fit in one standard atmosphere.
  3. 3.To go back the other way, divide by 760, or multiply by 0.0013157895.

Worked example: 25 atmospheres to torr

Formula
atm × 760 = Torr
Arithmetic
25 × 760 = 19,000 Torr
Answer
25 atm = 19,000 Torr

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

Atmospheres to torr conversion table

AtmospheresTorr
1 atm760 Torr
2 atm1,520 Torr
3 atm2,280 Torr
4 atm3,040 Torr
5 atm3,800 Torr
6 atm4,560 Torr
7 atm5,320 Torr
8 atm6,080 Torr
9 atm6,840 Torr
10 atm7,600 Torr
12 atm9,120 Torr
15 atm11,400 Torr
20 atm15,200 Torr
25 atm19,000 Torr
50 atm38,000 Torr
100 atm76,000 Torr
200 atm152,000 Torr
300 atm228,000 Torr
500 atm380,000 Torr
1000 atm760,000 Torr
2000 atm1,520,000 Torr
5000 atm3,800,000 Torr
10000 atm7,600,000 Torr

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 torr?

Exactly one seven-hundred-and-sixtieth of a standard atmosphere. Within a millionth of a millimetre of mercury, which is what it replaced, and still the unit of vacuum work.

How many torr are in a standard atmosphere?

One standard atmosphere is 760 torr, exactly. Going the other way, one torr is 0.0013157895 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 torr are in a standard atmosphere?
760. Exactly one seven-hundred-and-sixtieth of a standard atmosphere. Within a millionth of a millimetre of mercury, which is what it replaced, and still the unit of vacuum work.
How do I convert torr back to atmospheres?
Divide by 760, or multiply by 0.0013157895 — they are the same operation.

Other pressure conversions

Torr to atmospheres — the same conversion the other way.