Highly recommended. Without a car you are limited to 1-2 beaches near your accommodation. KTEL buses run only on main roads. Distances: Thessaloniki to Kassandra ~80km, Thessaloniki to Sarti ~130km.
KTEL bus: from Halkidiki bus station (Kavatatzoglou), 4-8 services/day, ~€12-15 to Kassandra, ~1.5h. Car: Egnatia highway → Moudania road, ~1-1.5h. Taxi/Transfer: €60-100 depending on destination.
Small car (e.g., Fiat Panda): €25-45/day in June, €35-60 in August. Mid-size (e.g., VW Polo): €35-70/day. Fuel: ~€1.80/liter. Book early at Thessaloniki Airport for best prices.
Main roads are in good condition. Kassandra has excellent roads. Sithonia has some narrow roads in the southern part. Drive carefully at night — goats on the road! Fines: seatbelts are mandatory.
Every larger village has at least 1 fuel station. In southern Sithonia (past Sarti), fill up before leaving — distances grow. Prices: ~€1.75-1.90/liter for unleaded. Cards accepted everywhere.
Take the ferry from Tripiti (near Ouranoupoli). It runs every 30-60 minutes, journey ~15 minutes. Ticket: ~€3/person, ~€10/car. Operates year-round, more frequently in summer.
Yes, Google Maps works very well in Halkidiki. Download offline maps beforehand in case of weak signal at remote beaches. Waze is also a good alternative for traffic info.
Taxis operate on meters. Examples: Thessaloniki Airport to Kassandra €70-90, to Sithonia €90-120. Within a village €5-10. Night +20%. Alternatively, there are transfer services (book online).