Convert psi to atmospheres

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Enter a value in psi and read the result in atmospheres. At 30 psi the converter shows 2.041379 atm, because one psi is 0.068046 atmospheres.

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How many atmospheres are in one psi?

One psi is 0.068046 atmospheres. You divide the number of psi by 14.6959, or multiply it by 0.068046, so the formula reads atm = psi ÷ 14.6959.

Both numbers are the ratio of the two definitions, rounded. A psi is 6,894.757 pascals and an atmosphere is 101,325 pascals[1], so the quotient is 0.068 046 0 and the IUPAC pressure conversion table prints the same value[2].

Because the atmosphere is more than fourteen times the larger unit, one psi lands below a tenth of an atmosphere. Thirty psi give 2.041379 atmospheres and a hundred psi give 6.804596. The converter shows six decimal places so that neighbouring gauge readings stay apart.

The same divisor covers the whole range. A reading of 14.7 psi comes to 1.000276 atmospheres, just over unity. Three thousand psi give 204.137892 atmospheres.

What is a psi, and what is a standard atmosphere?

A psi comes from one pound-force spread over one square inch[3]. That definition ties the unit to the customary system, and its value in SI units is 6,894.757 pascals[1].

The standard atmosphere describes air pressure at sea level and is exactly 101,325 pascals[1]. It is sometimes used as a reference pressure and carries the symbol atm[4].

One unit therefore comes from force and area, and the other out of the weight of the air itself. That is why the factor between them carries four decimal places.

Round service gauge with three scales on one dial: psi reaching 500 on the outside, bar reaching 35 in the middle and a temperature ring in °C inside, with the needle resting on zero
This gauge carries three scales on one dial. The outer one, marked psi, reaches 500. The middle one, marked bar, ends at 35, and the inner ring shows temperature in °C. The needle rests on zero even though one atmosphere surrounds the instrument, because a gauge measures pressure above its surroundings. Photo: shraga kopstein, Unsplash.

How do you convert psi to atm? Formula and example

The arithmetic comes down to one division. Three gauge readings follow, each worked out in full.

Thirty psi give 2.041379 atmospheres. Fifty psi come to 3.402298 atmospheres. Three thousand psi work out to 204.137892 atmospheres.

The atm to psi converter runs the calculation the other way. For the units printed on European gauges, the same reading goes through the psi to bar converter or the psi to kPa converter.

How many atmospheres is a given number of psi?

The first column gives the result in atmospheres and the second gives the same pressure in bar, a unit of exactly 100,000 pascals. The row with 14.7 psi shows how close that rounded figure is to one atmosphere.
PsiAtmospheresBar
1 psi0.068046 atm0.0689 bar
2 psi0.136092 atm0.1379 bar
5 psi0.34023 atm0.3447 bar
7 psi0.476322 atm0.4826 bar
8 psi0.544368 atm0.5516 bar
10 psi0.68046 atm0.6895 bar
12 psi0.816552 atm0.8274 bar
14 psi0.952643 atm0.9653 bar
14.7 psi1.000276 atm1.0135 bar
15 psi1.020689 atm1.0342 bar
20 psi1.360919 atm1.379 bar
25 psi1.701149 atm1.7237 bar
29 psi1.973333 atm1.9995 bar
30 psi2.041379 atm2.0684 bar
32 psi2.177471 atm2.2063 bar
35 psi2.381609 atm2.4132 bar
36 psi2.449655 atm2.4821 bar
40 psi2.721839 atm2.7579 bar
45 psi3.062068 atm3.1026 bar
50 psi3.402298 atm3.4474 bar
55 psi3.742528 atm3.7921 bar
60 psi4.082758 atm4.1369 bar
65 psi4.422988 atm4.4816 bar
70 psi4.763217 atm4.8263 bar
75 psi5.103447 atm5.1711 bar
80 psi5.443677 atm5.5158 bar
85 psi5.783907 atm5.8605 bar
90 psi6.124137 atm6.2053 bar
100 psi6.804596 atm6.8948 bar
110 psi7.485056 atm7.5842 bar
120 psi8.165516 atm8.2737 bar
130 psi8.845975 atm8.9632 bar
145 psi9.866665 atm9.9974 bar
150 psi10.206895 atm10.3421 bar
175 psi11.908044 atm12.0658 bar
200 psi13.609193 atm13.7895 bar
250 psi17.011491 atm17.2369 bar
300 psi20.413789 atm20.6843 bar
400 psi27.218386 atm27.579 bar
500 psi34.022982 atm34.4738 bar
750 psi51.034473 atm51.7107 bar
1,000 psi68.045964 atm68.9476 bar
1,500 psi102.068946 atm103.4214 bar
2,000 psi136.091928 atm137.8951 bar
3,000 psi204.137892 atm206.8427 bar
4,500 psi306.206838 atm310.2641 bar
5,000 psi340.22982 atm344.7379 bar
10,000 psi680.459639 atm689.4757 bar
A reading of 14.7 psi comes to 1.000276 atmospheres, because the full value of an atmosphere is 14.695 948 8 psi. Three thousand psi already make 204.137892 atmospheres.

What is real air pressure in psi?

Air pressure moves with the weather, and the standard atmosphere is an agreed value fixed once for every calculation. Three rows are official World Meteorological Organization records for sea-level air pressure[5]. The highest pressure recorded in the UK, 1,053.6 hPa at Aberdeen Observatory on 31 January 1902, comes from the Met Office[6].
Measured pressureWhere and whenAtmospheresPsi
1,089.1 hPaRecord above 750 m: Tosontsengel, Mongolia, 30 December 20041.0749 atm15.7961 psi
1,083.8 hPaRecord below 750 m: Agata, Russian Federation, 31 December 19681.0696 atm15.7192 psi
1,053.6 hPaUK record: Aberdeen Observatory, 31 January 19021.0398 atm15.2812 psi
1,013.25 hPaStandard atmosphere, the agreed value1 atm14.6959 psi
870 hPaLowest at sea level: the eye of Typhoon Tip, 12 October 19790.8586 atm12.6183 psi
The sea-level air pressure records run from 12.6183 to 15.7961 psi. The agreed value of 14.6959 psi is closer to the upper end of that span.

How many absolute atmospheres does a gauge reading show?

A gauge measures pressure above its surroundings, so with the needle on zero the line is at the surrounding air pressure, close to one atmosphere. Absolute pressure comes from adding 14.6959 psi to the reading.
Gauge readingAbsolute pressureAbsolute atmospheres
0 psi14.6959 psi1 atm
15 psi29.6959 psi2.0207 atm
30 psi44.6959 psi3.0414 atm
32 psi46.6959 psi3.1775 atm
50 psi64.6959 psi4.4023 atm
100 psi114.6959 psi7.8046 atm
200 psi214.6959 psi14.6092 atm
3,000 psi3,014.6959 psi205.1379 atm
The air in a tire inflated to 32 psi is at 46.6959 psi absolute, which is 3.1775 atmospheres. The psi to bar converter covers the psig and psia notation.

Which number formats does this converter accept?

The table shows what the field does with the ways a pressure usually reaches it from gauges, manuals and spreadsheets. The converter itself calculated every result.
What you typeWhat the converter showsNote
302.041379 atmA plain number is read as psi, because that’s what the field is labeled.
30 psi2.041379 atmThe psi symbol pasted along with the number is skipped, in capitals too.
30 psig2.041379 atmThe psig suffix marks a gauge reading. The field skips it, and the result stays gauge pressure, only in atmospheres.
14.7 psia1.000276 atmThe psia suffix marks absolute pressure. The field skips it, so the result is in absolute atmospheres.
2.50.170115 atmThe period is your decimal point, and that’s exactly how we read it.
2,50.170115 atmA comma with fewer than three digits after it is a decimal comma from a European document, so we read two and a half psi.
1.5000.102069 atmA single period is always read as a decimal point, so the field takes one and a half psi. A note under the field says: Read as 1.5. If you meant 1500, type 1500.
1,500102.068946 atmA comma followed by three digits groups thousands, so the field reads fifteen hundred psi. A note under the field says: Read as 1500. If you meant 1.5, type 1.5.
1/20.034023 atmA fraction with a slash is worked out for you, so half a psi doesn’t need to become 0.5 first.
-5-0.34023 atmA minus sign is accepted, so a vacuum gauge reading in psi converts too.
-80 kPa-0.789539 atmA pressure in another unit is converted by the field itself, minus sign included, as long as the minus sits right against the number.
- 80 kPaThe result field stays empty.A minus separated by a space isn’t joined to the number, so nothing is calculated. Type the minus right before the digit.

How do you convert psi to atm in a spreadsheet?

Excel carries a built-in function for pressure units, so it supplies the factor itself.

  1. Type the gauge reading in psi

    Put the number of psi in a cell, for example 30 in cell A2.

  2. Call the CONVERT function

    In the next cell type =CONVERT(A2,"psi","atm"). The function takes number, from_unit and to_unit[7].

  3. Show more decimal places

    Excel rounds the displayed result to the column width, so on the Home tab click Increase Decimal until six decimal places appear.

  4. Drag the formula down

    Grab the bottom right corner of the result cell and drag it along the column to convert a whole list of readings at once.

Convert Pounds per square inch (psi) to other units

psi to barpsi to kPa

Sources

  1. NIST Guide to the SI, Appendix B.9: Factors for Units Listed by Kind of Quantity or Field of Science — National Institute of Standards and Technology
  2. Quantities, Units and Symbols in Physical Chemistry (Green Book), 3rd edition, p. 233 — International Union of Pure and Applied Chemistry
  3. Pound per square inch — Wikipedia
  4. Standard atmosphere (unit) — Wikipedia
  5. Global Weather & Climate Extremes Archive, table of records — World Meteorological Organization
  6. National Meteorological Library and Archive Factsheet 9: Weather extremes — Met Office
  7. CONVERT function — Microsoft

Every figure in the tables was computed from the unit definitions and checked arithmetically before publication. Historical values and the names of local units come from the sources listed above.

Content last reviewed: · written and checked by the Arteon team

Frequently asked questions about converting psi to atm

How many atm is 30 psi?

Thirty psi come to 2.041379 atmospheres, or 2.0684 bar. That is the reading on a tire gauge set to 30 psi.

How many atm is 50 psi?

Fifty psi give 3.402298 atmospheres. In bar the same reading is 3.4474.

How many atm is 60 psi?

Sixty psi come to 4.082758 atmospheres, or 4.1369 bar. The relation is linear, so twice the psi gives twice the atmospheres.

How many atm is 100 psi?

A hundred psi come to 6.804596 atmospheres. In bar the same reading is 6.8948, close to seven times the air pressure at sea level.

How many atm is 3000 psi?

Three thousand psi come to 204.137892 atmospheres. In bar the same reading is 206.8427.

How many atm is 1 psi?

One psi is 0.068046 atmospheres. One atmosphere therefore comes to just under fifteen psi, or 14.695 948 8 to seven decimal places.

Is 14.7 psi one atmosphere?

A reading of 14.7 psi gives 1.000276 atmospheres. The full value is 14.695 948 8 psi, so rounding to 14.7 lifts the result by just under three ten-thousandths of an atmosphere.

Why does a gauge read zero when one atmosphere surrounds it?

A gauge measures pressure above its surroundings, so with the same pressure on both sides it points at zero. You get absolute pressure by adding 14.6959 psi to the reading.

How many atmospheres are in a tire inflated to 32 psi?

A reading of 32 psi answers to 2.177471 atmospheres of gauge pressure. The air inside is at 3.1775 atmospheres absolute, because the surrounding atmosphere adds to the reading.

What are the records for sea-level air pressure?

The World Meteorological Organization lists 1,089.1 hPa at Tosontsengel in Mongolia as the highest sea-level air pressure and 870 hPa in the eye of Typhoon Tip as the lowest. In psi that spans 12.6183 to 15.7961.

Arteon free tool screenshot: Convert psi to atmospheres

Have a question or a suggestion?

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