For a one-week trip to Hawaii in 2026, the cost of a rental car varies significantly by island and season, but the average total typically falls between $350 and $550. On the more populated islands like Oahu (Honolulu), you can often find "Economy" or "Compact" cars for around $45 to $60 per day ($315–$420 per week) if you book at least three weeks in advance. However, on Maui or Kauai, where supply is more limited and the demand for SUVs or Jeeps is higher, daily rates can easily climb to $80 or $100 per day, bringing a weekly total closer to $700. In 2026, prices peak during the winter holidays (December) and the summer rush (June-July), while the best deals are usually found in the "shoulder" months of May and October. It is important to factor in additional costs such as "concession recovery fees" at the airport, which can add 10-15% to your bill, and the high cost of fuel on the islands. To save money, many travelers are now using peer-to-peer sharing apps like Turo, which can sometimes offer lower daily rates than traditional agencies like Hertz or Avis.