The calculated distance (air line) between Santiago de Querétaro and San Miguel de Allende is approximately 32 miles respectively 52 kilometers.
By car or train, the actual journey to San Miguel de Allende is certainly longer, as only the direct route (as the crow flies) between Santiago de Querétaro and San Miguel de Allende has been calculated here.
Air line (approximately)
52 kilometers
28 nautical miles