Pressure

Inches of Water to mmHg

Convert inches of water to mmhg instantly. 1 inH2O = 1.8683201286 mmHg. Includes the exact factor, a conversion table of common values and the definition of both units.

inH2O
mmHg
One step, one exact factorInches of Waterwhat you have× 1.8683201286mmHgwhat you getBoth units are defined against the same base unit, so the factor is exact — never an approximation.

How to convert inches of water to mmhg

To convert inches of water to mmhg, multiply by 1.8683201286. 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.

mmHg = inH2O × 1.8683201286

Inches of Water to mmHg conversion table

The values people look up most often, rounded for reading. Use the calculator above for anything in between.

Inches of WatermmHg
1 inH2O1.86832 mmHg
2 inH2O3.73664 mmHg
3 inH2O5.60496 mmHg
5 inH2O9.341601 mmHg
10 inH2O18.683201 mmHg
20 inH2O37.366403 mmHg
25 inH2O46.708003 mmHg
50 inH2O93.416006 mmHg
100 inH2O186.832013 mmHg
500 inH2O934.160064 mmHg
1,000 inH2O1,868.32 mmHg

What is a inches of water?

A low-pressure unit used for ventilation and gas appliances.

What is a mmhg?

Millimetres of mercury, still the clinical unit for blood pressure.

The formula

mmHg = inH2O × 1.8683201286

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 mmHg

  1. Type the number of inches of water you want to convert.
  2. Read the result in mmhg straight away — there is no button to press.
  3. Check the table below for the values that come up most often, or reverse the conversion with the linked mmhg to inches of water page.

Inches of Water to mmHg — frequently asked questions

How many mmhg are in a inches of water?

One inches of water equals 1.8683201286 mmHg. mmHg = inH2O × 1.8683201286

What is the formula to convert inches of water to mmhg?

The formula is mmHg = inH2O × 1.8683201286. It is an exact definition rather than an approximation, so the conversion never drifts no matter how large the number.

How do I convert mmhg back to inches of water?

Divide instead of multiplying: one mmhg is 0.535240179 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 mmhg 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 mmhg.

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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