| Duncan to Blue Island (Illinois) | 741.87 mi (1,193.93 km) |
| Duncan to Blue Springs (Missouri) | 369.03 mi (593.90 km) |
| Duncan to Bluffdale (Utah) | 869.32 mi (1,399.04 km) |
| Duncan to Bluffton (Indiana) | 817.32 mi (1,315.35 km) |
| Duncan to Bluffton (South Carolina) | 992.14 mi (1,596.70 km) |
| Duncan to Blythe (California) | 956.58 mi (1,539.46 km) |
| Duncan to Blytheville (Arkansas) | 462.35 mi (744.08 km) |
| Duncan to Boca Raton (Florida) | 1,199.03 mi (1,929.65 km) |
| Duncan to Boerne (Texas) | 331.99 mi (534.28 km) |
| Duncan to Bogalusa (Louisiana) | 535.63 mi (862.02 km) |
| Duncan to Boiling Springs (South Carolina) | 904.36 mi (1,455.43 km) |
| Duncan to Boise (Idaho) | 1,160.68 mi (1,867.93 km) |
| Duncan to Bolingbrook (Illinois) | 726.37 mi (1,168.98 km) |
| Duncan to Bolivar (Missouri) | 328.73 mi (529.05 km) |
| Duncan to Bon Air (Virginia) | 1,153.19 mi (1,855.87 km) |
