How far is Decatur, IL, from Helena, MT?

The distance between Helena (Helena Regional Airport) and Decatur (Decatur Airport) is 1251 miles / 2014 kilometers / 1087 nautical miles.

The driving distance from Helena (HLN) to Decatur (DEC) is 1535 miles / 2470 kilometers, and travel time by car is about 27 hours 4 minutes.

Distance from Helena to Decatur

There are several ways to calculate the distance from Helena to Decatur. Here are two standard methods:

Vincenty's formula (applied above)

• 1251.454 miles
• 2014.021 kilometers
• 1087.484 nautical miles

Vincenty's formula calculates the distance between latitude/longitude points on the earth's surface using an ellipsoidal model of the planet.

Haversine formula

• 1248.720 miles
• 2009.620 kilometers
• 1085.108 nautical miles

The haversine formula calculates the distance between latitude/longitude points assuming a spherical earth (great-circle distance – the shortest distance between two points).

How long does it take to fly from Helena to Decatur?

The estimated flight time from Helena Regional Airport to Decatur Airport is 2 hours and 52 minutes.

What is the time difference between Helena and Decatur?

The time difference between Helena and Decatur is 1 hour. Decatur is 1 hour ahead of Helena.

Flight carbon footprint between Helena Regional Airport (HLN) and Decatur Airport (DEC)

On average, flying from Helena to Decatur generates about 164 kg of CO2 per passenger, and 164 kilograms equals 361 pounds (lbs). The figures are estimates and include only the CO2 generated by burning jet fuel.

Map of flight path and driving directions from Helena to Decatur

See the map of the shortest flight path between Helena Regional Airport (HLN) and Decatur Airport (DEC).

Airport information

Origin	Helena Regional Airport
City:	Helena, MT
Country:	United States
IATA Code:	HLN
ICAO Code:	KHLN
Coordinates:	46°36′24″N, 111°58′58″W

Destination	Decatur Airport
City:	Decatur, IL
Country:	United States
IATA Code:	DEC
ICAO Code:	KDEC
Coordinates:	39°50′4″N, 88°51′56″W