Do you need a vignette to reach Zagreb?
The Hungarian motorway vignette only covers the Hungarian section of your route. Once you cross into Croatia, a completely different toll or vignette system takes over — OptimÚt calculates the Hungarian leg for you, up to the border.
Border crossing
Via Letenye (M7): This cost/time covers the route to Letenye (the Hungarian-Croatian border, M7 motorway) only — Zagreb is about another 60 km from there, where Croatian tolls apply.
How to calculate it
Open OptimÚt, enter your own starting point in "From", and type Zagreb into "To" — OptimÚt automatically recognises it as an international destination and calculates the route, toll cost and required vignette(s) up to the border, for whichever of the crossings above turns out faster or cheaper for your specific starting point.