The E6B's two sides, taken apart: every job the wind side and the computer side do, as a calculator that shows its working.
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An E6B is a circular slide rule with a wind grid on the back. The wind side solves the wind triangle: slide the grid to your true airspeed, mark the wind, and read the correction angle and groundspeed. The computer side is a slide rule for anything that is a rate times a time (distance, fuel, climb, descent), with small windows for true airspeed and density altitude. Each job below is one of our calculators.
The wind triangle: correction angle, heading and groundspeed.
Headwind and crosswind components for a runway, gusts included.
Found in the computer side's airspeed window; the wind side starts from it.
Solve for time, groundspeed or distance, plus an ETA.
Burn for a leg, endurance to dry tanks, and what's left above the reserve.
Pressure altitude from the altimeter setting, then density altitude from the temperature.
Feet per nautical mile to the feet per minute your VSI has to show.
Where to start down and at what rate, and how far you glide.
A paper E6B makes you do the arithmetic, which is how you notice that a 25-knot quartering headwind at 110 knots TAS costs you 14 knots of groundspeed. These give the answer at once, then show the formula and a worked example on the same page, so the check-your-work habit survives. The nav log generator runs the whole chain for every leg of a trip, and the tools page has the rest, from weight and balance to the METAR decoder.
FlightDecide runs the same numbers for your aircraft and flight window, alongside the weather, NOTAMs, fuel and weight and balance, and shows where any of them crosses your own minimums.
Get FlightDecide on the App StoreEducational tools for flight-planning practice. They are advisory only and not a substitute for your POH, an official briefing, or your own judgment as pilot in command (14 CFR 91.3). Sources are cited on each calculator's page. Last reviewed: September 26, 2026.