Ferries from Koufonisi to Sifnos can peak at up to 2 daily sailings, Sailing frequency typically peaks in the summer months, with approximately 9 departures offered each week. While schedules may be reduced from Koufonisi to Sifnos in other seasons, ferry services are often still available.

Ferry travel from Koufonisi to Sifnos on average typically takes 4h 35m. The earliest ferry usually leaves from Koufonisi at 12:40, arriving to Sifnos at 18:10 The latest ferry departs at 15:35 and arrives at 19:55.