| Piqua to McHenry (Illinois) | 259.00 mi (416.82 km) |
| Piqua to McKeesport (Pennsylvania) | 232.40 mi (374.01 km) |
| Piqua to McKinleyville (California) | 2,074.09 mi (3,337.93 km) |
| Piqua to McKinney (Texas) | 837.98 mi (1,348.61 km) |
| Piqua to McLean (Virginia) | 384.63 mi (619.00 km) |
| Piqua to McMinnville (Oregon) | 1,989.05 mi (3,201.07 km) |
| Piqua to McMinnville (Tennessee) | 319.61 mi (514.36 km) |
| Piqua to McNair (Virginia) | 373.21 mi (600.63 km) |
| Piqua to McPherson (Kansas) | 727.45 mi (1,170.72 km) |
| Piqua to Mead Valley (California) | 1,863.41 mi (2,998.86 km) |
| Piqua to Meadow Woods (Florida) | 830.48 mi (1,336.53 km) |
| Piqua to Meadowbrook (Virginia) | 410.04 mi (659.89 km) |
| Piqua to Meadville (Pennsylvania) | 237.63 mi (382.43 km) |
| Piqua to Mebane (North Carolina) | 389.61 mi (627.02 km) |
| Piqua to Mechanicsville (Virginia) | 409.28 mi (658.68 km) |
