Distance between cities › USA › Maryland › McHenry, MD › Distance from McHenry to O Fallon Book Hotels

Distance from McHenry, MD to O Fallon, MO

Distance

694 mi

Time

13 hours 9 mins

Gas Cost

$65 - $126

There are 609.96 miles from McHenry to O Fallon in west direction and 694 miles (1,116.88 kilometers) by car, following the I-70 route.

McHenry and O Fallon are 13 hours 9 mins far apart, if you drive non-stop .

This is the fastest route from McHenry, MD to O Fallon, MO.

Please note the time difference between McHenry, MD and O Fallon, MO is 1 hour. The current time in McHenry is 12:55 pm and the current time in O Fallon is 11:55 am.

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Lowest Price Rental Cars in McHenry, MD

Planning on renting a car to go from McHenry, MD to O Fallon, MO? Here there are some offers to rent a car in McHenry, MD

Small

From $14

Intermediate

From $18

Full-size

From $24

SUVs

From $28

Vans

From $40

Compare rental car prices in McHenry »

Gas Consumption and Emissions

A car with a fuel efficiency of MPG will need 27.86 gallons of gas to cover the route between McHenry, MD and O Fallon, MO.

The estimated cost of gas to go from McHenry to O Fallon is $90.89.

During the route, an average car will release 545.88 pounds of CO₂ to the atmosphere. The carbon footprint would be 0.79 pounds of CO₂ per mile.

Average USA gas price used for calculation is $3.26 per gallon of regular gas. Price last updated on March 12, 2026.
Read more about our CO₂ calculation.

Halfway Point Between McHenry, MD and O Fallon, MO

If you want to meet halfway between McHenry, MD and O Fallon, MO or just make a stop in the middle of your trip, the exact coordinates of the halfway point of this route are 39.828772 and -84.767261, or 39º 49' 43.5792" N, 84º 46' 2.1396" W. This location is 346.89 miles away from McHenry, MD and O Fallon, MO and it would take approximately 6 hours 34 mins to reach the halfway point from both locations.

Closest City or Town to Halfway Point

The closest town to the halfway point is New Paris, OH, situated 355 miles from McHenry, MD and 345 miles from O Fallon, MO. It would take 6 hours 43 mins to go from McHenry to New Paris and 6 hours 35 mins to go from O Fallon to New Paris.