Quick answer
The distance reference we use for Puttgarden → Rødbyhavn is ≈ 10 nm one way. It is for fuel budgeting, not a navigation instruction.
- Enter your real cruising speed.
- Use total fuel burn for all engines in L/h.
- Change price per litre for your harbour or marina.
Formula: cost = distance ÷ speed × L/h fuel burn × price/L