Since Croatia officially adopted the Euro (€) in 2023, you no longer need to worry about the Kuna. For a trip in 2026, a safe estimate for daily cash needs is between €50 and €100 per person, assuming your accommodation is already paid for. While most restaurants, hotels, and larger shops in major hubs like Zagreb, Split, and Dubrovnik accept international credit cards (Visa/Mastercard), cash remains essential for smaller purchases. You will need physical Euros for local markets, small "konobas" (traditional taverns) in remote villages, bus tickets purchased on board, and for tipping—which is typically 10% to 15% in sit-down restaurants. It is generally better to withdraw cash from a local bank ATM using a travel card (like Wise or Revolut) to get the best exchange rate, rather than bringing large amounts of physical currency from home. Be aware that many public restrooms and small souvenir stalls on the islands still operate on a "cash-only" basis, so keeping a few small-denomination notes and coins is highly recommended.