| Irthlingborough to Devnya | 1,439.71 mi (2,317.00 km) |
| Irthlingborough to Dimitrovgrad | 1,409.44 mi (2,268.27 km) |
| Irthlingborough to Dobrich | 1,436.65 mi (2,312.06 km) |
| Irthlingborough to Dospat | 1,370.81 mi (2,206.11 km) |
| Irthlingborough to Dupnitsa | 1,302.28 mi (2,095.81 km) |
| Irthlingborough to Elhovo | 1,442.98 mi (2,322.25 km) |
| Irthlingborough to Etropole | 1,311.96 mi (2,111.40 km) |
| Irthlingborough to Gabrovo | 1,363.71 mi (2,194.67 km) |
| Irthlingborough to Gorna Oryahovitsa | 1,367.31 mi (2,200.47 km) |
| Irthlingborough to Gotse Delchev | 1,357.77 mi (2,185.12 km) |
| Irthlingborough to Harmanli | 1,426.47 mi (2,295.68 km) |
| Irthlingborough to Haskovo | 1,413.23 mi (2,274.37 km) |
| Irthlingborough to Ihtiman | 1,321.94 mi (2,127.45 km) |
| Irthlingborough to Isperih | 1,389.73 mi (2,236.55 km) |
| Irthlingborough to Kardzhali | 1,417.86 mi (2,281.83 km) |
