Standard atmospheres (atm)
The standard atmosphere is the average air pressure at sea level, defined as exactly 101,325 pascals, 760 mmHg or about 14.696 psi.
Convert standard atmospheres to any pressure unit
1 standard atmosphere = 14.69594878 pounds per square inch
Quick facts
- Unit
- Standard atmosphere (plural: standard atmospheres)
- Symbol
- atm
- Measures
- Pressure / Stress
- System
- Atmospheres & mercury
- Equals
- 101,325 pascals
- Definition
- Exactly 101,325 Pa.
- Also written
- atmosphere
1 standard atmosphere in other units
| Pounds per square inch | 14.69594878 psi |
| Bars | 1.01325 bar |
| Kilopascals | 101.325 kPa |
| Pascals | 101,325 Pa |
| Millimeters of mercury | 759.9998917 mmHg |
| Hectopascals | 1,013.25 hPa |
| Megapascals | 0.101325 MPa |
| Inches of mercury | 29.92125558 inHg |
What is a standard atmosphere?
The standard atmosphere is the average air pressure at sea level, defined as exactly 101,325 pascals, 760 mmHg or about 14.696 psi. It is used in chemistry (standard conditions), diving and high-pressure physics.
Where the standard atmosphere sits among pressure units
The standard atmosphere is number 35 of 44 on our scale of pressure units, ordered from smallest to largest.
What standard atmospheres are used for
- Chemistry: standard temperature and pressure
- Diving: every 10 m of seawater adds about 1 atm
- Describing high pressures ("300 atmospheres")
Standard atmospheres in real life
- At 10 m depth a diver is under about 2 atm absolute
- The Mariana Trench bottom is about 1,070 atm
Top standard atmosphere conversions
- Standard atmospheres to pounds per square inch
- Standard atmospheres to bars
- Standard atmospheres to kilopascals
- Standard atmospheres to pascals
- Standard atmospheres to millimeters of mercury
- Standard atmospheres to hectopascals
- Standard atmospheres to megapascals
- Standard atmospheres to inches of mercury
- Standard atmospheres to millibars
- Standard atmospheres to centimeters of water
- Standard atmospheres to inches of water
- Standard atmospheres to torr
Common amounts of standard atmospheres
- 0.1 atm
- 0.2 atm
- 0.3 atm
- 0.4 atm
- 0.5 atm
- 0.6 atm
- 0.7 atm
- 0.8 atm
- 0.9 atm
- 1 atm
- 1.5 atm
- 2 atm
- 2.5 atm
- 3 atm
- 3.5 atm
- 4 atm
- 4.5 atm
- 5 atm
- 6 atm
- 7 atm
- 7.5 atm
- 8 atm
- 9 atm
- 10 atm
- 11 atm
- 12 atm
- 13 atm
- 14 atm
- 15 atm
- 16 atm
- 17 atm
- 18 atm
- 19 atm
- 20 atm
- 21 atm
- 22 atm
- 23 atm
- 24 atm
- 25 atm
- 26 atm
- 27 atm
- 28 atm
- 29 atm
- 30 atm
- 31 atm
- 32 atm
- 33 atm
- 34 atm
- 35 atm
- 36 atm
- 37 atm
- 38 atm
- 39 atm
- 40 atm
- 41 atm
- 42 atm
- 43 atm
- 44 atm
- 45 atm
- 46 atm
- 47 atm
- 48 atm
- 49 atm
- 50 atm
- 51 atm
- 52 atm
- 53 atm
- 54 atm
- 55 atm
- 56 atm
- 57 atm
- 58 atm
- 59 atm
- 60 atm
- 61 atm
- 62 atm
- 63 atm
- 64 atm
- 65 atm
- 66 atm
- 67 atm
- 68 atm
- 69 atm
- 70 atm
- 71 atm
- 72 atm
- 73 atm
- 74 atm
- 75 atm
- 76 atm
- 77 atm
- 78 atm
- 79 atm
- 80 atm
- 81 atm
- 82 atm
- 83 atm
- 84 atm
- 85 atm
- 86 atm
- 87 atm
- 88 atm
- 89 atm
- 90 atm
- 91 atm
- 92 atm
- 93 atm
- 94 atm
- 95 atm
- 96 atm
- 97 atm
- 98 atm
- 99 atm
- 100 atm
- 110 atm
- 120 atm
- 130 atm
- 140 atm
- 150 atm
- 160 atm
- 170 atm
- 180 atm
- 190 atm
- 200 atm
- 210 atm
- 220 atm
- 230 atm
- 240 atm
- 250 atm
- 260 atm
- 270 atm
- 280 atm
- 290 atm
- 300 atm
- 310 atm
- 320 atm
- 330 atm
- 340 atm
- 350 atm
- 360 atm
- 370 atm
- 380 atm
- 390 atm
- 400 atm
- 410 atm
- 420 atm
- 430 atm
- 440 atm
- 450 atm
- 460 atm
- 470 atm
- 480 atm
- 490 atm
- 500 atm
- 600 atm
- 700 atm
- 800 atm
- 900 atm
- 1,000 atm
- 1,200 atm
- 1,500 atm
- 2,000 atm
- 2,500 atm
- 3,000 atm
- 4,000 atm
- 5,000 atm
- 10,000 atm
Convert standard atmospheres to all 45 other units
Metric (SI)
- atm to bar
- atm to kPa
- atm to Pa
- atm to hPa
- atm to MPa
- atm to mbar
- atm to GPa
- atm to barg
- atm to kbar
- atm to dbar
- atm to cbar
- atm to µbar
Atmospheres & mercury
Water column
US & imperial
- atm to psi
- atm to psig
- atm to ksi
- atm to psf
- atm to Mpsi
- atm to ozf/in²
- atm to LT/in²
- atm to tonf/ft²
- atm to pdl/ft²
Gravitational metric & CGS
Scientific
Convert to standard atmospheres
- Pounds per square inch to standard atmospheres
- Bars to standard atmospheres
- Kilopascals to standard atmospheres
- Pascals to standard atmospheres
- Millimeters of mercury to standard atmospheres
- Hectopascals to standard atmospheres
- Megapascals to standard atmospheres
- Inches of mercury to standard atmospheres
- Millibars to standard atmospheres
- Centimeters of water to standard atmospheres
- Inches of water to standard atmospheres
- Torr to standard atmospheres
Frequently asked questions
What is a standard atmosphere?
The standard atmosphere is the average air pressure at sea level, defined as exactly 101,325 pascals, 760 mmHg or about 14.696 psi.
How is the standard atmosphere defined?
Exactly 101,325 Pa.
How many pounds per square inch are in a standard atmosphere?
One standard atmosphere equals 14.69594878 pounds per square inch.
How many bars are in a standard atmosphere?
One standard atmosphere equals 1.01325 bars.
How many kilopascals are in a standard atmosphere?
One standard atmosphere equals 101.325 kilopascals.