1 millimeter of water [mmH2O] = 0.073556 millimeter of mercury [mmHg]
Example: 1 millimeter of water [mmH2O] equals 0.073556 millimeter of mercury [mmHg].
Examples
1 millimeter of water [mmH2O] = 0.073556 millimeter of mercury [mmHg]
2 millimeter of water [mmH2O] = 0.147112 millimeter of mercury [mmHg]
5 millimeter of water [mmH2O] = 0.36778 millimeter of mercury [mmHg]
10 millimeter of water [mmH2O] = 0.735559 millimeter of mercury [mmHg]
20 millimeter of water [mmH2O] = 1.471118 millimeter of mercury [mmHg]
25 millimeter of water [mmH2O] = 1.838898 millimeter of mercury [mmHg]
Practical Uses for millimeter water to millimeter mercury
tire inflationcompressors and pumpsHVAC and plumbingengineering specifications
Sources and Accuracy
Pressure conversions use pascal as the reference unit and include common engineering, weather, tire, and laboratory pressure units.
Displayed results are rounded for readability. The calculator keeps enough precision for everyday use and switches to scientific notation for very large or very small values. Last reviewed: 2026-08-14.
About These Units
millimeter of water [mmH2O]
Definition
The millimeter of water (mmH2O) is a pressure unit used to express measurements in this converter.
History
This unit is included because it appears in practical measurement systems, technical references, product specifications, or everyday conversion needs.
Current use
Use millimeter of water when comparing pressure values, checking specifications, converting between systems, or preparing quick estimates.
millimeter of mercury [mmHg]
Definition
The millimeter of mercury (mmHg) is a pressure unit used to express measurements in this converter.
History
This unit is included because it appears in practical measurement systems, technical references, product specifications, or everyday conversion needs.
Current use
Use millimeter of mercury when comparing pressure values, checking specifications, converting between systems, or preparing quick estimates.
Advertisement728 × 90
How to Convert
Enter the value in the “From value” field.
Confirm the source unit is millimeter of water [mmH2O].
Confirm the target unit is millimeter of mercury [mmHg].
Read the instant result and formula.
Where This Conversion Is Used
tire inflationcompressors and pumpsHVAC and plumbingengineering specifications
millimeter water to millimeter mercury Conversion Chart
How do I convert millimeter of water to millimeter of mercury?
Use this formula: 1 millimeter of water [mmH2O] = 0.073556 millimeter of mercury [mmHg] Enter your value in the calculator and the result updates instantly.
How many millimeter of mercury are in 1 millimeter of water?
1 millimeter of water [mmH2O] equals 0.073556 millimeter of mercury [mmHg].
Can I reverse this conversion?
Yes. Use the swap button in the calculator or open the related reverse conversion link when it is listed on this page.