The calculated distance (air line) between Phnom Penh and Svay Rieng is approximately 68 miles respectively 110 kilometers.
By car or train, the actual journey to Svay Rieng is certainly longer, as only the direct route (as the crow flies) between Phnom Penh and Svay Rieng has been calculated here.
Air line (approximately)
110 kilometers
59 nautical miles