How many atmospheres are in 1 inch of mercury?

1 inch of mercury equals 0.0334211 atm.

How do I convert atmospheres back to inches of mercury?

Use the reverse converter: 1 atmosphere equals 29.9213 inHg.

Yes. It uses the exact SI/NIST definitions of each unit and shows up to 6 significant digits.

To convert inches of mercury to atmospheres, multiply the value by 0.0334210609.

atm = inHg × 0.0334210609

20 inHg × 0.0334210609 = 0.6684 atm

Inch Of Mercury (inHg): Used for barometric pressure in US weather and aviation. About 3,386.389 pascals.
Atmosphere (atm): Standard atmosphere: exactly 101,325 pascals, the average air pressure at sea level.

How do I convert inches of mercury to atmospheres?: To convert inches of mercury to atmospheres, multiply the value by 0.0334210609.
How many atmospheres are in 1 inch of mercury?: 1 inch of mercury equals 0.0334211 atm.
How many atmospheres are in 10 inches of mercury?: 10 inHg equals 0.334211 atm.
How do I convert atmospheres back to inches of mercury?: Use the reverse converter: 1 atmosphere equals 29.9213 inHg.
Is this converter accurate?: Yes. It uses the exact SI/NIST definitions of each unit and shows up to 6 significant digits.