Passage Time with Current Calculator
Fill in the values and the answer updates as you type.
How the Passage Time with Current Calculator works
Speed over the ground = speed through the water + current speed along the track, where a favourable current is positive and a foul current is negative. Time = distance ÷ speed over the ground, added to your departure time to give the arrival clock time. This assumes a steady current along the whole route, but real currents change with the tide, so plan the trip in legs for long passages. No result appears if the current is stronger than your boat speed against you. Example: with Distance 42 NM, Speed through the water 6 kt, Current along your track (negative = against you) 1.5 kt, Departure hour (0 to 23) 8, and Departure minute (0 to 59) 30, the result is Speed over the ground (kt) = 7.5; Time underway = 5 h 36 min; Arrival time = 14:06.
Inputs and results
The Passage Time with Current Calculator takes 5 inputs and gives 5 results.
What you enter
- Distance (NM) — starts at 42.
- Speed through the water (kt) — starts at 6.
- Current along your track (negative = against you) (kt) — starts at 1.5.
- Departure hour (0 to 23) — starts at 8.
- Departure minute (0 to 59) — starts at 30.
What you get
- Speed over the ground (kt)
- Time underway
- Arrival time
- Minutes gained (negative = lost) versus still water
- Time in still water
Example: Passage Time with Current Calculator with the starting values
With distance 42 NM, speed through the water 6 kt, current along your track (negative = against you) 1.5 kt, departure hour (0 to 23) 8 and departure minute (0 to 59) 30, the calculator returns:
| Speed over the ground (kt) | 7.5 |
|---|---|
| Time underway | 5 h 36 min |
| Arrival time | 14:06 |
| Minutes gained (negative = lost) versus still water | 84 |
| Time in still water | 7 h 00 min |
Change any value above and the results update straight away.
Passage Time with Current Calculator FAQ
How do I use the Passage Time with Current Calculator?
Enter distance, speed through the water, current along your track (negative = against you) and departure hour (0 to 23) in the fields, then read speed over the ground (kt), time underway, arrival time and minutes gained (negative = lost) versus still water in the result panel. The answer updates as you type, and you can press Calculate or Enter to refresh it. Use “Copy link” to share your exact numbers with someone else.
What does the Passage Time with Current Calculator calculate?
Speed over the ground and arrival time with a fair or foul current. It returns speed over the ground (kt), time underway, arrival time and minutes gained (negative = lost) versus still water from the 5 values you provide.
What values does the Passage Time with Current Calculator start with?
It opens with distance 42 NM, speed through the water 6 kt, current along your track (negative = against you) 1.5 kt and departure hour (0 to 23) 8 so you can see a working result straight away. Replace them with your own numbers, or press Reset to return to these starting values.
Is the Passage Time with Current Calculator free and private?
Yes. It is free, needs no account, and runs in your browser, so nothing you type is sent to or stored on our servers. See the Privacy Policy for details.
Can I rely on the Passage Time with Current Calculator for important decisions?
Treat the result as a well-rounded estimate. Real situations often have details a general calculator cannot know, so confirm important decisions with a qualified professional. See the Disclaimer for more.