Millibar to millimeter mercury conventional

Reference table

How the conversion works

The input is converted into Pa using the source factor and offset, then into millimeter mercury conventional. This keeps unit definitions consistent across the pressure collection.

Definitions and sources

Factors are maintained in the versioned unit dataset. Output is rounded to your selected significant digits; calculation uses JavaScript double precision.

• https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b9
• https://www.bipm.org/en/publications/si-brochure

How to use this tool

1. Enter a finite numeric value in millibar.
2. Choose the significant digits for your result.
3. Copy or download the result, including its formula.

Try this example

10

Accuracy and scope

Gauge and absolute pressure cannot be interconverted without reference pressure. Water/mercury columns use conventional definitions, not an actual measured fluid column.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.