No-Fly Time Calculator

Enter when you surfaced from your last dive and when your flight takes off. The tool checks the wait against the DAN guidelines and a 24 hour margin.

Results update as you type.

Diving you did

Repetitive or multi-day diving, which covers most dive holidays. DAN minimum: 18 hours.

Surfaced from last dive at

The time you reached the surface after your last dive, not when you left the boat.

Flight takes off at

Takeoff time, not the time you leave for the airport.

Flight day

Time from surfacing to takeoff

DAN minimum met

18 hours meets the 18 hour DAN minimum. PADI and a 2024 medical review use 24 hours as the general rule, which would mean flying at 16:00 the next day or later.

DAN minimum wait: 18 h
Earliest takeoff (DAN minimum): 10:00 the next day
Earliest takeoff with 24 h: 16:00 the next day

These are minimums for divers without symptoms. Don't board with any sign of decompression sickness. Get medical advice first, from a doctor who knows diving medicine or from DAN.

Was this calculator useful?

These tools are educational planning aids; they are not a substitute for dive training, current printed tables or a dive computer. Verify results against your training and always plan within the limits of your certification.

About the no-fly time

An airliner cabin usually sits at the air pressure of 1,800-2,400 m (6,000-8,000 ft), according to DAN. Nitrogen left in your body after diving can form bubbles when the pressure drops, so you wait for it to leave before you fly.

The wait is counted from the moment you surface after your last dive until the plane takes off.

With your numbers

Enter valid values to see the calculation worked through with your numbers.

Formula

Earliest takeoff

Tfly = Tsurface + W

Your wait

Δt = Ttakeoff − Tsurface

Where

Tsurface: time you surfaced from the last dive
W: 12 h for one no-decompression dive, 18 h for repetitive or multi-day diving, 24 h for decompression dives
Ttakeoff: flight departure time

How it's calculated

Minimum waits from the 2002 DAN/UHMS Flying After Diving Workshop: 12 hours after one no-decompression dive, 18 hours after repetitive or multi-day diving. For decompression dives the workshop says substantially longer than 18 hours; the tool uses 24 hours from DAN's current summary.
The margin line is 24 hours, from the PADI blog and the Mitchell 2024 review in Diving and Hyperbaric Medicine. For decompression dives it matches the minimum.
The wait is counted from surfacing after the last dive to takeoff, in whole minutes. The flight day is counted from the day of the last dive.
Status: too soon below the minimum, DAN minimum met from the minimum up to 24 hours, 24 h margin met at 24 hours or more.

Good to know

Use the longest of three numbers: this minimum, the flight wait from your dive table and your dive computer's no-fly time.
The guidelines were written for cabin altitudes of 610-2,438 m (2,000-8,000 ft). DAN treats a flight that stays below 610 m as needing no special wait.
A drive over a high mountain pass counts the same way. DAN treats any ascent to altitude after diving as added decompression stress.
No guideline gives a shorter wait for nitrox, so pick the diving type as if you had used air.

How to use the no-fly time calculator

1
Pick the diving you did. After a dive holiday this is almost always several dives in a day or several days of diving.
2
Enter the time you surfaced from your last dive, then your takeoff time and day.
3
Read the status. If it says too soon, move the flight or skip the last dive, and use the earliest takeoff time to plan.

What the result means

The DAN minimum is the shortest wait that the 2002 DAN/UHMS workshop considered acceptable for divers without symptoms. It lowers the risk but does not remove it, and a longer wait lowers it further.

The 24 hour line comes from PADI's general rule and a 2024 medical review (Mitchell), which suggest 24 hours for most recreational diving. If your table or computer gives a longer wait, use that one.

Planning a flight at 10:00 after a week of diving? The 18 hour minimum means surfacing by 16:00 the day before, and a 24 hour margin moves that to 10:00 the day before.

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