Separate spending categories
Accommodation, major retail and many transport tickets can often stay on a payment card. Ordinary T-money loading has a clearer cash need. Keeping these categories separate stops an all-in daily budget from inflating the amount you carry.
Use a visible buffer
The planner’s standard buffer is the greater of ₩20,000≈£10.5 or 10% of planned cash spending. It is a heuristic for resilience, not an official government figure. Change it to low or high to see the effect.
Stage the cash
The result recommends an initial portion and a later top-up. Check ATM fees, card issuer charges and exchange terms yourself because those vary by bank, machine and home-country account and should not be hard-coded into a timeless calculator.