The calculated distance (air line) between Phnom Penh and Mỹ Tho is approximately 128 miles respectively 207 kilometers.
By car or train, the actual journey to Mỹ Tho is certainly longer, as only the direct route (as the crow flies) between Phnom Penh and Mỹ Tho has been calculated here.
Air line (approximately)
207 kilometers
112 nautical miles