Quick Diversion Calculator (Heading, Time, Fuel)
Weather ahead, divert now: bearing and distance to the alternate plus today's wind become heading, ETE and fuel — the 60-second cockpit drill, computed.
The checkride drill expects this in your head within ±5° and ±2 minutes — bearing eyeballed off the chart, clock code for the crab, nm-per-minute for the time. This tool is the answer key for practicing exactly that.
Formula
⚠️ For flight planning and education only — verify with official sources and certified equipment. Not for primary navigation.
Weather ahead, divert now: bearing and distance to the alternate plus today's wind become heading, ETE and fuel — the 60-second cockpit drill, computed.
About Quick Diversion Calculator (Heading, Time, Fuel)
Diversions are where flight planning meets a deadline measured in cloud height. The ACS expects a heading, time and fuel estimate to an alternate within minutes, by hand; this calculator runs the full solution — wind triangle on the new bearing, variation applied, ETE and fuel from the resulting ground speed — both as the answer key for practicing the mental drill and as the fast check when a real wall of weather makes the decision for you.
How to use Quick Diversion Calculator (Heading, Time, Fuel)
- 1Enter — sensible defaults are pre-filled so you see a worked result immediately.
- 2Read the live results: .
- 3Check the "With your numbers" line to see the formula wind triangle on the new bearing → MH = TH + var; ETE = dist/GS; fuel = ETE × flow substituted step by step.
- 4Adjust inputs (or flip the unit toggle) until the scenario matches yours, then copy or share the result.
Why use Quick Diversion Calculator (Heading, Time, Fuel)?
- ✓Instant, free and private — every calculation runs in your browser, nothing is uploaded
- ✓Built on the published formula wind triangle on the new bearing → MH = TH + var; ETE = dist/GS; fuel = ETE × flow with sources cited on the page
- ✓The checkride drill expects this in your head within ±5° and ±2 minutes — bearing eyeballed off the chart, clock code for the crab, nm-per-minute for the time. This tool is the answer key for practicing exactly that.
- ✓Switch units, tweak any input and watch every result update live
Frequently asked questions
What's the field-expedient way to get the bearing and distance?+
Pencil edge from present position to the alternate, read the angle against any nearby VOR compass rose (they're printed in magnetic — handy), and step the distance with thumb-widths calibrated to the chart scale (a sectional thumb ≈ 8–10 nm). Thirty seconds, ±5° and ±3 nm — entirely adequate to start the turn while refining.
Turn first or compute first?+
Turn first, roughly: put the nose within 20° of the alternate immediately (weather behind you grows no closer), then refine heading, time and fuel from the stabilized platform. The examiner's sequence — turn, time, then tune/talk — encodes the priority: a perfect solution flown two minutes late toward the weather is worse than a rough one flown now.
How do I practice this for the checkride efficiently?+
Reverse this tool: pick random present-position/alternate pairs on your sectional, solve by hand with the clock code and nm-per-minute pace, then enter the same numbers here and score yourself. Within 5° of heading and 2 minutes of ETE consistently and the task is checkride-dead. Ten reps an evening gets most pilots there in a week.
What makes a good diversion alternate in the real event?+
Behind-or-abeam beats ahead (you've seen that weather), bigger beats closer-but-marginal (runway length, services, instrument approaches if you're rated), and known beats optimal (the field you've used accepts you without study). Fuel reserves arbitrate everything — our bingo-fuel calculator formalizes the trigger that should have fired before the diversion got urgent.
Related Field tools
Sunrise & Sunset Calculator
Exact rise, set, solar noon and day length for any place and date — the NOAA solar equations with the refraction fine print included.
● LiveGolden Hour & Blue Hour Calculator
Tonight's golden hour and blue hour, computed from sun elevation — the photographer's light windows with the angles that define them.
● LiveDay Length Calculator
Hours of daylight for any date and latitude, how fast it's changing, and the swing between your solstices.
● Live