| Merthyr Tudful to Hutchinson (Minnesota) | 3,929.57 mi (6,324.03 km) |
| Merthyr Tudful to Hutto (Texas) | 4,759.39 mi (7,659.49 km) |
| Merthyr Tudful to Hyattsville (Maryland) | 3,520.91 mi (5,666.35 km) |
| Merthyr Tudful to Hybla Valley (Virginia) | 3,535.63 mi (5,690.05 km) |
| Merthyr Tudful to Idaho Falls (Idaho) | 4,603.66 mi (7,408.87 km) |
| Merthyr Tudful to Idylwood (Virginia) | 3,534.40 mi (5,688.07 km) |
| Merthyr Tudful to Ilchester (Maryland) | 3,501.81 mi (5,635.62 km) |
| Merthyr Tudful to Immokalee (Florida) | 4,306.95 mi (6,931.37 km) |
| Merthyr Tudful to Imperial (California) | 5,302.50 mi (8,533.54 km) |
| Merthyr Tudful to Imperial Beach (California) | 5,370.16 mi (8,642.43 km) |
| Merthyr Tudful to Independence (Kentucky) | 3,829.17 mi (6,162.45 km) |
| Merthyr Tudful to Independence (Missouri) | 4,205.03 mi (6,767.35 km) |
| Merthyr Tudful to Indian Trail (North Carolina) | 3,851.61 mi (6,198.57 km) |
| Merthyr Tudful to Indiana (Pennsylvania) | 3,537.02 mi (5,692.28 km) |
| Merthyr Tudful to Indianapolis (Indiana) | 3,854.33 mi (6,202.95 km) |
