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About this tool
Convert millimeters of mercury to atmospheres instantly. Free, bidirectional, and fully in-browser.
1 millimeter of mercury equals 0.001315789661 atmospheres — enter any millimeter of mercury value to convert it to atmospheres instantly. This Millimeter of mercury to Atmosphere converter is a client-side tool: it applies a single multiplication (atm = mmHg × 0.001315789661) in your browser, updates the moment you type, and works in both directions — edit either field, or press swap, to convert atmospheres back to millimeters of mercury. A reference table lists common millimeter of mercury values already converted, and nothing you enter is sent to a server.
Open Millimeter of mercury to Atmosphere Converter on AltFTool — it loads instantly in your browser.
Type the value you want to convert into the Millimeter of mercury field.
Read the equivalent in atmospheres in the result field, and copy it if needed.
Use the decimal-places slider for more or less precision, or press swap to convert atmospheres to millimeters of mercury.
The result updates as you type, and the swap button flips the conversion to atmosphere → millimeter of mercury without reloading.
The conversion uses the precise factor (atm = mmHg × 0.001315789661), so the number matches a manual calculation to the decimal places you choose.
A slider sets 0–10 decimal places, and very small or very large results switch to scientific notation instead of rounding to zero.
Everything runs locally in your browser — no upload, no account, no limit on conversions.
One millimeter of mercury is 0.001315789661 atmospheres. Multiply the millimeter of mercury value by 0.001315789661 to convert. For example, 10 mmHg = 0.01315789661 atm.
atm = mmHg × 0.001315789661. This tool applies it automatically and shows a worked example: 10 mmHg = 0.01315789661 atm.
Yes. Press the swap button, or type into the atmosphere field, and the tool converts atmospheres to millimeters of mercury using the inverse of the same relationship.
It uses the standard pressure definition (atm = mmHg × 0.001315789661), not a rounded approximation, so results are exact to the number of decimal places you select.
Yes. The converter is a browser-side script with no network calls: your values are never uploaded, and once the page has loaded it keeps working without a connection.
Add the Millimeter of mercury to Atmosphere Converter widget to your blog or website — free, responsive, no signup. Just keep the “Widget by AltFTool” credit link visible.
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