Distance between cities › USA › Illinois › Rio, IL › Distance from Rio to Custer Book Hotels

Distance from Rio, IL to Custer, MT

Distance

1,127 mi

Time

20 hours 7 mins

Gas Cost

$105 - $204

There are 923.17 miles from Rio to Custer in northwest direction and 1,127 miles (1,813.73 kilometers) by car, following the I-90 route.

Rio and Custer are 20 hours 7 mins far apart, if you drive non-stop .

This is the fastest route from Rio, IL to Custer, MT.

Please note the time difference between Rio, IL and Custer, MT is 1 hour. The current time in Rio is 4:12 am and the current time in Custer is 3:12 am.

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Lowest Price Rental Cars in Rio, IL

Planning on renting a car to go from Rio, IL to Custer, MT? Here there are some offers to rent a car in Rio, IL

Small

From $14

Intermediate

From $18

Full-size

From $24

SUVs

From $28

Vans

From $40

Compare rental car prices in Rio »

Gas Consumption and Emissions

A car with a fuel efficiency of MPG will need 45.28 gallons of gas to cover the route between Rio, IL and Custer, MT.

The estimated cost of gas to go from Rio to Custer is $147.69.

During the route, an average car will release 887.07 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 Rio, IL and Custer, MT

If you want to meet halfway between Rio, IL and Custer, MT or just make a stop in the middle of your trip, the exact coordinates of the halfway point of this route are 43.70858 and -98.5278, or 43º 42' 30.888" N, 98º 31' 40.08" W. This location is 563.70 miles away from Rio, IL and Custer, MT and it would take approximately 10 hours 3 mins to reach the halfway point from both locations.

Closest City or Town to Halfway Point

The closest town to the halfway point is Plankinton, SD, situated 578 miles from Rio, IL and 551 miles from Custer, MT. It would take 10 hours 20 mins to go from Rio to Plankinton and 9 hours 51 mins to go from Custer to Plankinton.