Paying electronically has improved a lot in the last dozen or so years, but my typical strategy had always been to keep $50-100 of local currency in my front po

Paying electronically has improved a lot in the last dozen or so years, but my typical strategy had always been to keep $50-100 of local currency in my front pocket, and then another $200 usd in my money belt (along with my passport) for a typical day. Between food and drink, lunch, busfare etc $100 generally covered most expenses beyond tickets to events, and then $200 USD was usually enough to solve any significant problems if you miss your bus ride home or whatever. If you sprain your ankle in some castle ruins, you likely don't want to spend half the afternoon hobbling around historic cobblestone roads in a village somewhere looking for an ATM to get taxi fare back to the hotel. Taxi drivers rarely turn down USD. That said, ATM fees internationally, depending on your card issuer, can be pretty expensive, ATM fees + forex fees can amount to over 10% if you're only pulling out $100/day. If you don't mind the risk, pulling out the maximum amount of cash per day (usually $400 I've noticed) gets total fees down to about 4%. If you're a student backpacker on a budget for weeks on end these fees can be a substantial fraction of your travel savings/budget.