We calculated distance with our calculator and with the help of International map agencies and distance between Riga and Inverness is 120 km.
If you go from Riga to Inverness, with normal traffic conditions and non-stop driving, you reach final destination in 1,5 hours.
Depend on car conditions and fuel quality, to travel from Riga to Inverness with car transport, you need 7 gallons gallons of petrol, which will cost around 10 $ with average prices.