E6B Flight Computer
A faithful, two-sided classic E6B — but interactive. Drag the calculator side like the metal one for time-speed-distance, fuel, TAS and density altitude, then hit Turn over for the wind side to solve the wind triangle for heading and groundspeed.
Apply your own magnitude — 12 can mean 1.2, 12 or 120. Aligning a value on the inner ring under the outer ring fixes one ratio all the way round, which is how the slide rule multiplies and divides.
Time · speed · distance
Set ground speed over the 60 ▲ rate index, then read distance (outer) over time in minutes (inner). Leave one box blank to solve for it.
Calculator side — the circular slide rule
The E6B's calculator face is a circular slide rule: two logarithmic scales, a fixed outer ring printed on the aluminium faceplate and a translucent rotating inner disc. Lining up a number on the inner ring under a number on the outer ring sets a single ratio that holds everywhere around the dial — which is how it multiplies and divides. The tabs beside the dial walk through each computation and show the exact answer.
What you can compute on the calculator side:
- Multiplication & division: set a value over the unit (10) index, then read products and quotients straight off the rings.
- Time–speed–distance: put ground speed (outer) over the ▲ 60 rate index, then read distance over time-in-minutes. Example: 120 kt over 60 → 60 NM above 30 min.
- Fuel consumption: rate, time and quantity — set gallons-per-hour over the 60 index and read fuel used over the time.
- True airspeed & density altitude: set pressure altitude against air temperature in the window to read density altitude, then read CAS across as true airspeed.
- True altitude correction: correct indicated altitude for non-standard temperature.
- Climb / descent — feet per nautical mile: distance to climb, gradient, glide ratio and the rate of climb required.
- Conversions: nautical ↔ statute ↔ kilometres (the NAUT / STAT / KM index arrows), feet ↔ metres, and gallons ↔ litres ↔ pounds of fuel.
- Temperature: °C ↔ °F.
Wind side — the wind triangle
Hit Turn over for the iconic wind face: a translucent rotating azimuth compass rose over a sliding grid card of speed arcs and wind-correction lines, centred on the grommet, with the true index ▲ at the top. Set the wind, rotate your true course up to the index, and the tool plots the wind dot and draws the solved triangle. It reads out your wind correction angle, true heading and ground speed, plus the head/tail-wind and crosswind components for a runway.
Prefer to just type the numbers? Use our density altitude, crosswind, and weight & balance calculators.
Studying for your FAA written?
Practice the concepts behind these numbers with ACS-aligned questions, AI explanations, and the cited FAA reference — free to start.