Inches of Water to Inches of Mercury
Convert inches of water to inches of mercury instantly. 1 inH2O = 0.0735559028 inHg. Includes the exact factor, a conversion table of common values and the definition of both units.
How to convert inches of water to inches of mercury
To convert inches of water to inches of mercury, divide by 13.5951019897 (multiply by 0.0735559028). The relationship is fixed, so the same factor works for any quantity — there is nothing to look up and nothing that changes with temperature, location or context.
inHg = inH2O × 0.0735559028
Inches of Water to Inches of Mercury conversion table
The values people look up most often, rounded for reading. Use the calculator above for anything in between.
| Inches of Water | Inches of Mercury |
|---|---|
| 1 inH2O | 0.073556 inHg |
| 2 inH2O | 0.147112 inHg |
| 3 inH2O | 0.220668 inHg |
| 5 inH2O | 0.36778 inHg |
| 10 inH2O | 0.735559 inHg |
| 20 inH2O | 1.471118 inHg |
| 25 inH2O | 1.838898 inHg |
| 50 inH2O | 3.677795 inHg |
| 100 inH2O | 7.35559 inHg |
| 500 inH2O | 36.777951 inHg |
| 1,000 inH2O | 73.555903 inHg |
What is a inches of water?
A low-pressure unit used for ventilation and gas appliances.
What is a inches of mercury?
The aviation altimeter unit: 29.92 inHg is standard sea-level pressure.
The formula
inHg = inH2O × 0.0735559028
Every result on this page comes from this formula. Nothing is rounded until the final display, so figures match a spreadsheet to the cent.
How to use the Inches of Water to Inches of Mercury
- Type the number of inches of water you want to convert.
- Read the result in inches of mercury straight away — there is no button to press.
- Check the table below for the values that come up most often, or reverse the conversion with the linked inches of mercury to inches of water page.
Inches of Water to Inches of Mercury — frequently asked questions
How many inches of mercury are in a inches of water?
One inches of water equals 0.0735559028 inHg. inHg = inH2O × 0.0735559028
What is the formula to convert inches of water to inches of mercury?
The formula is inHg = inH2O × 0.0735559028. It is an exact definition rather than an approximation, so the conversion never drifts no matter how large the number.
How do I convert inches of mercury back to inches of water?
Divide instead of multiplying: one inches of mercury is 13.5951019897 inH2O. The reverse converter is linked in the related tools list.
Is this conversion exact?
Yes. Both units are defined against the same base unit by international agreement, so the factor is exact — any rounding you see is only in the display, which you can widen by entering more decimal places.
Is this inches of water to inches of mercury free to use?
Yes. Every calculator on the site is free, needs no sign-up, and runs entirely in your browser, so your figures never leave your device.
What people search for
This page answers each of these searches. They are the exact phrases visitors use to find the inches of water to inches of mercury.
- inches of water to inches of mercury
- 1 inches of water to inches of mercury
- how many inches of mercury in a inches of water
- inh2o2inhg
- inches of water in inches of mercury
- inches of water to inches of mercury converter
- convert inches of water to inches of mercury
About this calculator
Written and reviewed by The Samsung Calculator editorial team. Every calculator is written against a published formula, reviewed against at least one independent reference implementation, and dated when it changes.
Last reviewed August 19, 2026 · Calculation runs client-side · No data collected · Report an error