How many mmHg is 1 atmosphere?

1 standard atmosphere (atm) equals exactly 760 millimeters of mercury (mmHg). This relationship is a definition in the International System of Units — 1 atm = 101,325 Pa, and 1 mmHg = 133.322 Pa, giving 101325 / 133.322 ≈ 760.

How do I convert atm to mmHg manually?

Multiply the atmosphere value by 760. For example, 2 atm × 760 = 1,520 mmHg. To convert mmHg back to atm, divide by 760.

What is the difference between mmHg and Torr?

mmHg (millimeters of mercury) and Torr are nearly identical units. 1 Torr is defined as 1/760 of a standard atmosphere, and 1 mmHg = 1.000000142 Torr. For practical purposes they are interchangeable in blood pressure and laboratory use.

What is standard blood pressure in atm?

Normal systolic blood pressure is about 120 mmHg, which equals 120 / 760 ≈ 0.158 atm. Diastolic is about 80 mmHg ≈ 0.105 atm. Blood pressure is almost universally reported in mmHg rather than atm.

What is 0.5 atm in mmHg?

0.5 atm equals 380 mmHg. This pressure corresponds roughly to the air pressure at an altitude of about 5,500 meters (18,000 feet).

When would I use atm versus mmHg?

Atmospheres are common in chemistry and general physics. mmHg is the standard for blood pressure, ophthalmology (eye pressure), vacuum systems, and historical barometric readings. Use this converter whenever you encounter specs in one unit but need the other.

Atmospheres to mmHg Converter

Name: Atmospheres to mmHg Converter
Availability: InStock
Author: Nham Vu

Enter a pressure in atmospheres and get the mmHg equivalent instantly, with reverse mmHg-to-atm conversion included.

Converter

Pressure in atmospheres (atm)

Result in mmHg

Reverse: mmHg to atmospheres

Pressure in mmHg

Result in atm

Reference Table

Atmospheres (atm) mmHg

0.01 atm 7.6

0.1 atm 76

0.25 atm 190

0.5 atm 380

0.75 atm 570

1 atm 760

1.5 atm 1,140

2 atm 1,520

3 atm 2,280

5 atm 3,800

10 atm 7,600

100 atm 76,000

Summary

Enter a pressure in atmospheres and get the mmHg equivalent instantly, with reverse mmHg-to-atm conversion included.

How it works

Enter the pressure value in atmospheres (atm) in the top input field.
The mmHg result appears instantly with no button press needed.
Use the reverse field to convert mmHg back to atmospheres.
Click "Copy" next to any result to copy the value to your clipboard.
Check the reference table for common atm-to-mmHg values at a glance.

Use cases

Convert barometric pressure from atm to mmHg for weather station readings.
Translate blood pressure reference values from atm to mmHg for medical context.
Convert chemistry lab vacuum pressures from atm to mmHg for equipment specs.
Check altitude pressure data in mmHg when source uses atm.
Verify gas cylinder pressures that mix atm and mmHg across different suppliers.
Convert industrial process pressures from atm to mmHg for legacy gauges.
Translate atmospheric pressure for scuba diving calculations using mmHg gauges.
Compare standard atmosphere values across unit systems in physics coursework.

Frequently Asked Questions

Last updated: 2026-07-01 · Reviewed by Nham Vu