Is 1 mmHg the same as 1 Torr?

Nearly, but not exactly. The Torr is defined as exactly 1/760 of a standard atmosphere (101,325 Pa), giving 1 Torr = 133.322... Pa. The mmHg is defined by the physical properties of mercury (density 13,595.1 kg/m³ at 0°C, standard gravity 9.80665 m/s²), giving 1 mmHg = 133.3224 Pa. The difference is approximately 0.0014%, which matters only in high-precision vacuum science.

What is the exact conversion factor from mmHg to Torr?

1 mmHg = 1.000013596 Torr. This factor comes from dividing the exact Pa value of 1 mmHg (133.3224 Pa) by the exact Pa value of 1 Torr (101325/760 Pa). For everyday use the two units are interchangeable.

When does the mmHg vs Torr difference matter?

The ~0.0014% difference only matters in high-precision vacuum calibration, national metrology institute standards, or academic physics work where absolute accuracy below 1 Pa is required. In medicine, chemistry, and engineering the units are used interchangeably.

How do I convert mmHg to Torr manually?

Multiply the mmHg value by 1.000013596. For example, 760 mmHg × 1.000013596 ≈ 760.010 Torr. For most practical purposes, treat 1 mmHg as 1 Torr.

What is standard atmospheric pressure in mmHg and Torr?

Standard atmospheric pressure is defined as exactly 760 Torr (= 101,325 Pa). In mmHg it is 759.990 mmHg (≈ 760 mmHg). The small difference reflects the distinct definitions of the two units.

mmHg to Torr Converter

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

Convert mmHg to Torr (and back) using the exact factor — they differ by only 0.0014%, so this also explains when the distinction matters.

Converter

Pressure in mmHg

Result in Torr

Reverse: Torr to mmHg

Pressure in Torr

Result in mmHg

Factor used: 1 mmHg = 1.000013596 Torr (exact physical definition). For most applications, treating 1 mmHg = 1 Torr introduces less than 0.0014% error.

Reference Table

mmHg Torr

1 mmHg 1.000014 Torr

10 mmHg 10.00014 Torr

100 mmHg 100.0014 Torr

120 mmHg 120.0016 Torr

200 mmHg 200.0027 Torr

300 mmHg 300.0041 Torr

500 mmHg 500.0068 Torr

760 mmHg 760.0103 Torr

1,000 mmHg 1,000.014 Torr

5,000 mmHg 5,000.068 Torr

10,000 mmHg 10,000.14 Torr

Summary

Convert mmHg to Torr (and back) using the exact factor — they differ by only 0.0014%, so this also explains when the distinction matters.

How it works

Enter the pressure value in mmHg in the top input field.
The converter multiplies your value by 1.000013596 to get Torr.
The result updates instantly as you type.
Use the reverse field to convert Torr back to mmHg.
Click "Copy" next to any result to copy it to the clipboard.
Check the reference table for common mmHg-to-Torr values.

Use cases

Convert blood pressure readings (mmHg) to Torr for physics calculations.
Express barometric pressure in Torr for vacuum science applications.
Cross-check pressure sensor specs that mix mmHg and Torr units.
Verify the exact mmHg vs Torr difference in high-precision metrology work.
Translate medical pressure values to Torr for gas chromatography instruments.
Convert partial-pressure readings for scientific literature comparisons.

Frequently Asked Questions

Last updated: 2026-07-24 · Reviewed by Nham Vu