Atmospheres to Millimeters Of Mercury
Type a value in either box to convert between atmospheres and millimeters of mercury. The factor is 760.
| Atmospheres | Millimeters Of Mercury |
|---|---|
| 1 atm | 759.999892 mmHg |
| 2 atm | 1519.999783 mmHg |
| 3 atm | 2279.999675 mmHg |
| 5 atm | 3799.999459 mmHg |
| 10 atm | 7599.998917 mmHg |
| 25 atm | 18999.997293 mmHg |
| 50 atm | 37999.994586 mmHg |
| 100 atm | 75999.989173 mmHg |
How to use
- Enter a value in the Atmospheres field.
- The Millimeters Of Mercury figure appears immediately — no button to press.
- Typing in the Millimeters Of Mercury field converts back to Atmospheres the same way.
- Use the reference table for the values that come up most often.
Atmospheres to Millimeters Of Mercury formula
The factor from atmospheres to millimeters of mercury is 759.999892.
mmHg = atm × 759.999892
Why this factor: the atmosphere and the millimeter of mercury are both defined against the pascal, so dividing one definition by the other gives 759.999892 directly. Both definitions are set out in full below.
To go the other way, divide by 759.999892 — or use the Millimeters Of Mercury to Atmospheres converter, which is the same calculation reversed.
Worked example
Given 760 atm, multiplying by 759.999892 yields 577599.917711 mmHg.
760 atm × 759.999892 = 577599.917711 mmHg
The converter above does this for any value you type, in either direction.
What is an atmosphere?
A standard atmosphere is a fixed reference pressure, originally average sea-level air pressure.
Definition: Defined as exactly 101,325 pascals — an exact convention, not a measurement.
Where it is used: Chemistry reference conditions, diving pressure, and high-pressure physics.
What is a millimeter of mercury?
A millimeter of mercury is the pressure exerted by a 1 mm column of mercury, still standard in medicine.
Definition: Defined as exactly 133.322387415 pascals.
Where it is used: Blood pressure readings, intraocular pressure, and respiratory gas pressures.
Worth knowing: Blood pressure is universally reported in mmHg even in fully metric countries — one of the most durable legacy units in medicine.
Atmospheres vs Millimeters Of Mercury
The atmosphere and the millimeter of mercury belong to the same family of units, so converting between them is usually a matter of shifting a decimal point or applying a small whole-number factor.
Frequently asked questions
How many millimeters of mercury are in an atmosphere?
One atmosphere equals 759.999892 millimeters of mercury.
What is the formula to convert atmospheres to millimeters of mercury?
Multiply the number of atmospheres by 759.999892. To reverse it, divide by 759.999892 instead.
How do I convert millimeters of mercury back to atmospheres?
Divide by 759.999892, which is the same as multiplying by 0.00131578966.
How many millimeters of mercury are in 10 atmospheres?
10 atm works out to 7599.998917 mmHg.
Is there anything to watch out for with millimeters of mercury?
Blood pressure is universally reported in mmHg even in fully metric countries — one of the most durable legacy units in medicine.
How is the atmosphere defined?
Defined as exactly 101,325 pascals — an exact convention, not a measurement.