How many Torr are in one atmosphere?

One standard atmosphere (1 atm) equals exactly 760 Torr. This relationship is part of the original definition of the standard atmosphere and is exact by definition.

How do I convert atmospheres to Torr manually?

Multiply the atm value by 760. For example, 2 atm × 760 = 1,520 Torr.

What is a Torr and where is it used?

The Torr is a unit of pressure named after Evangelista Torricelli, who invented the mercury barometer. It is widely used in vacuum science, gas chromatography, mass spectrometry, and physics. 1 Torr is defined as 1/760 of a standard atmosphere, which is approximately 133.322 Pa.

Is Torr the same as mmHg?

Nearly, but not exactly. One Torr is defined as exactly 1/760 atm, while 1 mmHg is based on the physical pressure exerted by one millimeter of mercury. The difference is about 0.000014%, so they are used interchangeably in most practical applications.

What is standard atmospheric pressure in Torr?

Standard atmospheric pressure is exactly 760 Torr (equivalent to 101,325 Pa or 14.696 psi). This is the reference point used to define the Torr unit.

Can I convert partial atmospheres like 0.5 atm?

Yes. Multiply any atm value — including decimals — by 760. So 0.5 atm = 0.5 × 760 = 380 Torr.

Atmospheres to Torr Converter

Enter a pressure in atmospheres and get the Torr equivalent instantly — includes reverse conversion and a reference table.

Converter

Pressure in atmospheres (atm)

Result in Torr

Reverse: Torr to atmospheres

Pressure in Torr

Result in atm

Reference Table

Atmospheres (atm) Torr

0.001 atm 0.76 Torr

0.01 atm 7.6 Torr

0.1 atm 76 Torr

0.5 atm 380 Torr

1 atm 760 Torr

2 atm 1,520 Torr

5 atm 3,800 Torr

10 atm 7,600 Torr

50 atm 38,000 Torr

100 atm 76,000 Torr

1,000 atm 760,000 Torr

Summary

This converter turns any atmosphere (atm) value into Torr in real time using the exact factor 1 atm = 760 Torr as defined by international standards. The Torr is named after Evangelista Torricelli and is used widely in vacuum science, gas chromatography, and physics. All computation runs in your browser with no server round-trips. A reverse field lets you go from Torr back to atm, and a reference table covers common pressures from vacuum work to high-pressure applications.

How it works

Enter the pressure value in atmospheres in the top input field.
The converter multiplies your value by 760 to get Torr.
The result updates instantly as you type.
Use the reverse field to convert Torr back to atmospheres.
Click "Copy" next to any result to copy it to the clipboard.
Check the reference table for common atm-to-Torr values.

Use cases

Convert gas pressure readings from atm to Torr for vacuum system specifications.
Translate chemistry lab pressures into Torr for gas chromatography instruments.
Express partial pressures in Torr for atmospheric science calculations.
Convert boiling point pressure values from atm to Torr in lab reports.
Verify vacuum pump ratings specified in Torr against atmospheric references.
Cross-check pressure readings that mix atm and Torr units in scientific literature.

Frequently Asked Questions

Last updated: 2026-06-18 · Reviewed by Nham Vu