How many atm is 1 mmHg?

0.00131578966114 atm, which is 133.322387415 / 101,325. It scales straight up: 10 mmHg is 0.0131578966114 atm, 100 mmHg is 0.131578966114 atm, 500 mmHg is 0.65789483057 atm, 750 mmHg is 0.986842245855 atm and 760 mmHg is 1.00000014247 atm. Answers print to twelve significant digits, and displayed magnitudes below 0.000001 switches to exponential notation, so 0.0001 mmHg reads 1.31578966114e-7 atm rather than a row of zeroes.

What is the formula for mmHg to atm?

atm = original mmHg × 133.322387415 / 101,325 exactly for the stated conventional definitions. In reverse, mmHg = original atm × 101,325 / 133.322387415. The displayed reverse factor 759.999891726 is rounded; multiplying by it only approximates the exact division. Decimal-rational arithmetic preserves the written scalar and factors, then rounds outputs beyond twelve significant digits. Swap units retains the typed scalar.

Why is 760 mmHg not exactly 1 atm?

Torr is exactly 101,325/760 Pa, approximately 133.322368421 Pa; conventional mmHg is exactly 133.322387415 Pa. The unit-size difference is about 1.4 parts in ten million. Thus 760 mmHg displays as 1.00000014247 atm and 1 atm as 759.999891726 mmHg. Whether rounded digits agree depends on the quantity, rounding boundary and required precision. Torr is absent from the menu; the converter does not treat these definitions as identical.

What is 1 atm in mmHg, kPa and psi?

759.999891726 mmHg, 101.325 kPa and 14.6959487755 psi, alongside 101,325 Pa and 1.01325 bar. You do not have to ask for those one at a time: put 1 in the From box with atmospheres selected, or use the Swap units button from this page, and the converter works out every pressure unit in the category at once and lists them under the answer.

Can I convert inches of mercury here?

Not as a listed unit. The pressure category holds pascals, kilopascals, bar, pounds per square inch, atmospheres and millimetres of mercury, and inHg is not one of them. An inch is exactly 25.4 millimetres, so only if the source supplies the same density/gravity mercury convention 1 inHg is 25.4 mmHg, which this page shows as 0.033421057393 atm. Multiply your inHg figure by 25.4 and type that. Going the other way, 760 mmHg is 29.9212598425 inHg. A different inHg reference convention needs its own definition; source labels alone do not establish it.

Why does the list under the answer not repeat mmHg?

The list shows every other unit in the category, skipping the one you are converting from, so on this page it reads pascals, kilopascals, bar, pounds per square inch and atmospheres. The readout strip also carries an Uncommon units switch labelled Show 1 more, because mmHg is filed as the one uncommon pressure unit. On this page turning it on changes nothing you can see: the unit it would add is the one already sitting in the From box.

Does it matter whether my figure is gauge or absolute?

The converter preserves the supplied pressure reference and has no gauge-to-absolute mode. Absolute pressure is relative to vacuum; gauge pressure is relative to a supplied reference. To derive absolute pressure separately, supply the applicable ambient pressure and add the signed gauge quantity before converting. One standard atmosphere is a defined unit, not a measurement of current ambient pressure. As a separate hypothetical calculation, a signed −100 mmHg gauge quantity with a supplied 760 mmHg ambient gives 660 mmHg absolute, displayed as 0.868421176352 atm. An original 100 mmHg absolute instead displays as 0.131578966114 atm.

Why does the page open on mmHg and atm when I last converted something else?

This focused page opens on Millimeter of mercury and Atmosphere, while preserving the main converter’s saved unit pair. When storage is usable, a saved value and uncommon-unit preference can travel between pages. Its suffix must still match From. Valid deliberate scalar edits can save those fields after a short delay; invalid or incomplete drafts preserve the saved record. Unusable or conflicting records remain until you use Forget saved settings, which keeps the current conversion on screen. Your input and converted values are calculated in the browser and are not uploaded by the converter. The definitions arrive with the page, so conversion needs no external data lookup and keeps working offline after the page has loaded. The core conversion needs no account. Copy result copies the displayed headline without digit-grouping commas; each visible conversion row has its own Copy button. Displayed and copied values round to twelve significant digits. If native copying fails, a complete selectable summary identifies the input, selected pair and conventions and includes every unit in the category, including uncommon units.

mmHg to Atm Converter

The conventional millimetre of mercury is a millimetre of mercury at 13,595.1 kg/m³ under a gravity of 9.80665 m/s², which works out to exactly 133.322387415 pascals, and a standard atmosphere is exactly 101,325 pascals. So mmHg to atm is one multiplication: atm = mmHg × 133.322387415 / 101,325, using the exact ratio of those stored definitions; dividing by the rounded 759.999891726 only approximates it. That makes 1 mmHg 0.00131578966114 atm, 100 mmHg 0.131578966114 atm, 500 mmHg 0.65789483057 atm, 700 mmHg 0.921052762798 atm and 760 mmHg 1.00000014247 atm, which is just over 1 rather than exactly 1 because a torr and a conventional mmHg are not quite the same size. This page opens the converter with mmHg in the From box and atmospheres in the To box, whatever pair you converted last, and the list under the answer carries the same pressure in pascals, kilopascals, bar and pounds per square inch. It changes the units on a number and nothing else: a converted figure is still just a quantity, and what it means in a given setting is not something arithmetic can tell you.

From

To0.00131578966114

Category: Pressure

Base unit: pascal

Uncommon units: Show 1 more

One standard atmosphere is 101,325 Pa. mmHg is the conventional 133.322387415 Pa, distinct from the torr (exactly 101,325/760 Pa). The psi coefficient is rounded to 6,894.757293168 Pa. Converting units preserves gauge or absolute reference; it does not add ambient pressure.

Results round to 12 significant digits using the listed unit definitions. Input must have a finite numeric magnitude and at most 512 significant digits. Type a single decimal or scientific number; a matching From unit suffix is accepted. Commas and grouped spaces separate thousands; decimal commas, fractions and compound measurements are refused.

1 mmHg in every pressure unit

PascalPa
133.322387415
KilopascalkPa
0.133322387415
Barbar
0.00133322387415
Pound per square inchpsi
0.0193367774595
Atmosphereatm
0.00131578966114

Selectable complete conversion

Unit Converter — Pressure
Input: 1 (Millimeter of mercury, mmHg)
Result: 0.00131578966114 atm (Atmosphere)
Displayed values round to 12 significant digits.
One standard atmosphere is 101,325 Pa. mmHg is the conventional 133.322387415 Pa, distinct from the torr (exactly 101,325/760 Pa). The psi coefficient is rounded to 6,894.757293168 Pa. Converting units preserves gauge or absolute reference; it does not add ambient pressure.
All other units:
Pascal (Pa): 133.322387415
Kilopascal (kPa): 0.133322387415
Bar (bar): 0.00133322387415
Pound per square inch (psi): 0.0193367774595
Atmosphere (atm): 0.00131578966114

Common questions

How many atm is 1 mmHg?: 0.00131578966114 atm, which is 133.322387415 / 101,325. It scales straight up: 10 mmHg is 0.0131578966114 atm, 100 mmHg is 0.131578966114 atm, 500 mmHg is 0.65789483057 atm, 750 mmHg is 0.986842245855 atm and 760 mmHg is 1.00000014247 atm. Answers print to twelve significant digits, and displayed magnitudes below 0.000001 switches to exponential notation, so 0.0001 mmHg reads 1.31578966114e-7 atm rather than a row of zeroes.
What is the formula for mmHg to atm?: atm = original mmHg × 133.322387415 / 101,325 exactly for the stated conventional definitions. In reverse, mmHg = original atm × 101,325 / 133.322387415. The displayed reverse factor 759.999891726 is rounded; multiplying by it only approximates the exact division. Decimal-rational arithmetic preserves the written scalar and factors, then rounds outputs beyond twelve significant digits. Swap units retains the typed scalar.
Why is 760 mmHg not exactly 1 atm?: Torr is exactly 101,325/760 Pa, approximately 133.322368421 Pa; conventional mmHg is exactly 133.322387415 Pa. The unit-size difference is about 1.4 parts in ten million. Thus 760 mmHg displays as 1.00000014247 atm and 1 atm as 759.999891726 mmHg. Whether rounded digits agree depends on the quantity, rounding boundary and required precision. Torr is absent from the menu; the converter does not treat these definitions as identical.
What is 1 atm in mmHg, kPa and psi?: 759.999891726 mmHg, 101.325 kPa and 14.6959487755 psi, alongside 101,325 Pa and 1.01325 bar. You do not have to ask for those one at a time: put 1 in the From box with atmospheres selected, or use the Swap units button from this page, and the converter works out every pressure unit in the category at once and lists them under the answer.
Can I convert inches of mercury here?: Not as a listed unit. The pressure category holds pascals, kilopascals, bar, pounds per square inch, atmospheres and millimetres of mercury, and inHg is not one of them. An inch is exactly 25.4 millimetres, so only if the source supplies the same density/gravity mercury convention 1 inHg is 25.4 mmHg, which this page shows as 0.033421057393 atm. Multiply your inHg figure by 25.4 and type that. Going the other way, 760 mmHg is 29.9212598425 inHg. A different inHg reference convention needs its own definition; source labels alone do not establish it.
Why does the list under the answer not repeat mmHg?: The list shows every other unit in the category, skipping the one you are converting from, so on this page it reads pascals, kilopascals, bar, pounds per square inch and atmospheres. The readout strip also carries an Uncommon units switch labelled Show 1 more, because mmHg is filed as the one uncommon pressure unit. On this page turning it on changes nothing you can see: the unit it would add is the one already sitting in the From box.
Does it matter whether my figure is gauge or absolute?: The converter preserves the supplied pressure reference and has no gauge-to-absolute mode. Absolute pressure is relative to vacuum; gauge pressure is relative to a supplied reference. To derive absolute pressure separately, supply the applicable ambient pressure and add the signed gauge quantity before converting. One standard atmosphere is a defined unit, not a measurement of current ambient pressure. As a separate hypothetical calculation, a signed −100 mmHg gauge quantity with a supplied 760 mmHg ambient gives 660 mmHg absolute, displayed as 0.868421176352 atm. An original 100 mmHg absolute instead displays as 0.131578966114 atm.
Why does the page open on mmHg and atm when I last converted something else?: This focused page opens on Millimeter of mercury and Atmosphere, while preserving the main converter’s saved unit pair. When storage is usable, a saved value and uncommon-unit preference can travel between pages. Its suffix must still match From. Valid deliberate scalar edits can save those fields after a short delay; invalid or incomplete drafts preserve the saved record. Unusable or conflicting records remain until you use Forget saved settings, which keeps the current conversion on screen. Your input and converted values are calculated in the browser and are not uploaded by the converter. The definitions arrive with the page, so conversion needs no external data lookup and keeps working offline after the page has loaded. The core conversion needs no account. Copy result copies the displayed headline without digit-grouping commas; each visible conversion row has its own Copy button. Displayed and copied values round to twelve significant digits. If native copying fails, a complete selectable summary identifies the input, selected pair and conventions and includes every unit in the category, including uncommon units.

Results round to 12 significant digits using the listed unit conventions. Many factors are exact definitions; psi and parsec use rounded coefficients. Temperature includes scale offsets. Days and weeks are fixed-duration units, and unit conversion does not determine calendar dates, ambient pressure or a software label’s convention.