| Herndon to Portage (Michigan) | 484.59 mi (779.87 km) |
| Herndon to Portage (Wisconsin) | 701.70 mi (1,129.27 km) |
| Herndon to Portales (New Mexico) | 1,473.21 mi (2,370.90 km) |
| Herndon to Porterville (California) | 2,271.36 mi (3,655.40 km) |
| Herndon to Portland (Maine) | 491.69 mi (791.31 km) |
| Herndon to Portland (Oregon) | 2,326.97 mi (3,744.90 km) |
| Herndon to Portland (Tennessee) | 525.04 mi (844.96 km) |
| Herndon to Portland (Texas) | 1,376.26 mi (2,214.88 km) |
| Herndon to Portsmouth (New Hampshire) | 445.09 mi (716.30 km) |
| Herndon to Portsmouth (Ohio) | 299.34 mi (481.74 km) |
| Herndon to Portsmouth (Virginia) | 157.12 mi (252.86 km) |
| Herndon to Post Falls (Idaho) | 2,052.25 mi (3,302.79 km) |
| Herndon to Potomac (Maryland) | 10.77 mi (17.34 km) |
| Herndon to Potomac Park (California) | 2,282.95 mi (3,674.05 km) |
| Herndon to Pottstown (Pennsylvania) | 128.18 mi (206.29 km) |
