Air Miles Calculator

Distance between Seattle, WA (BFI) and Decatur, IL (DEC)

Flight distance from Seattle to Decatur (Seattle Boeing Field – Decatur Airport) is 1742 miles / 2803 kilometers / 1514 nautical miles. Estimated flight time is 3 hours 47 minutes.

Driving distance from Seattle (BFI) to Decatur (DEC) is 2148 miles / 3457 kilometers and travel time by car is about 35 hours 19 minutes.

Map of flight path and driving directions from Seattle to Decatur.

Shortest flight path between Seattle Boeing Field (BFI) and Decatur Airport (DEC).

How far is Decatur from Seattle?

There are several ways to calculate distances between Seattle and Decatur. Here are two common methods:

Vincenty's formula (applied above)
  • 1741.983 miles
  • 2803.451 kilometers
  • 1513.742 nautical miles

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

Haversine formula
  • 1737.835 miles
  • 2796.774 kilometers
  • 1510.137 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).

Airport information


A Seattle Boeing Field
City: Seattle, WA
Country: United States Flag of United States
IATA Code: BFI
ICAO Code: KBFI
Coordinates: 47°31′47″N, 122°18′7″W

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

Time difference and current local times

The time difference between Seattle and Decatur is 2 hours. Decatur is 2 hours ahead of Seattle.

Time Difference

Seattle, WA

 PST

Decatur, IL

 CST

Carbon dioxide emissions

Estimated CO2 emissions per passenger is 196 kg (431 pounds).

Frequent Flyer Miles Calculator

Seattle (BFI) → Decatur (DEC).

Distance:
1742
Elite level bonus:
0
Booking class bonus:
0

In total

Total frequent flyer miles:
1742

Round trip?