| Hertford to Devnya | 1,408.63 mi (2,266.97 km) |
| Hertford to Dimitrovgrad | 1,375.80 mi (2,214.14 km) |
| Hertford to Dobrich | 1,406.16 mi (2,263.00 km) |
| Hertford to Dospat | 1,335.87 mi (2,149.87 km) |
| Hertford to Dupnitsa | 1,267.29 mi (2,039.50 km) |
| Hertford to Elhovo | 1,410.08 mi (2,269.30 km) |
| Hertford to Etropole | 1,278.16 mi (2,057.01 km) |
| Hertford to Gabrovo | 1,330.81 mi (2,141.73 km) |
| Hertford to Gorna Oryahovitsa | 1,334.96 mi (2,148.41 km) |
| Hertford to Gotse Delchev | 1,322.47 mi (2,128.30 km) |
| Hertford to Harmanli | 1,392.90 mi (2,241.66 km) |
| Hertford to Haskovo | 1,379.45 mi (2,220.02 km) |
| Hertford to Ihtiman | 1,287.58 mi (2,072.16 km) |
| Hertford to Isperih | 1,358.81 mi (2,186.79 km) |
| Hertford to Kardzhali | 1,383.67 mi (2,226.80 km) |
