What the E6B calculator solves
Choose a function from the list. Each calculator starts with a worked example, recalculates as you type and ends with How it is calculated, the same steps you would follow on paper or on the wheel.
| Function | What you enter | What you get |
|---|---|---|
| Heading and ground speed | True course, true airspeed, wind | Wind correction angle, true and magnetic heading, ground speed |
| Find the wind | Heading, airspeed, track, ground speed | The wind you are flying in |
| Crosswind | Runway, wind, gust, your limit | Crosswind and headwind or tailwind components |
| Pressure altitude | Field elevation, altimeter setting | Pressure altitude and station pressure |
| Density altitude | Elevation, altimeter, temperature, dewpoint | Density altitude, dry and with humidity |
| True airspeed | Calibrated airspeed, pressure altitude, temperature | True airspeed, Mach number, equivalent airspeed |
| Standard atmosphere | Altitude | ISA temperature, pressure and density |
| Time, speed and distance | Any two of the three | The third one |
| Fuel | Flight time, burn rate, reserve | Fuel required, endurance and weight |
| Top of descent | Altitudes, ground speed, descent rate | Where to start down |
| Climb | Altitudes, climb rate, ground speed | Time, distance, fuel and gradient |
| Conversions and cloud base | Units, temperature and dewpoint | Equivalents and an estimated cumulus base |
Weather and planning tools have their own pages: the METAR decoder, TAF decoder, weight and balance calculator and VFR nav log. To practice on the dial itself, open the E6B simulator.
How the answers are checked
Pilots act on these numbers, so the math is tested against published FAA material rather than against itself. The same tests run every time the site is built.
- Wind triangle. The Pilot's Handbook of Aeronautical Knowledge (PHAK, FAA-H-8083-25C, chapter 16) flies a true course of 090° at 120 knots with the wind from 045° at 40 knots and gets a true heading of 076° and a ground speed of 88 knots. Its flight-planning example (true course 031°, wind 360° at 10 knots, 115 knots, 7° E variation, 2° deviation) gives headings of 028° true, 021° magnetic and 023° compass at 106 knots. Both come out the same here.
- Crosswind. PHAK Sample Problem 10, runway 17 with the wind from 140° at 25 knots, gives a 22 knot headwind and a 13 knot crosswind.
- Pressure altitude. All 32 rows of the PHAK altimeter-correction table (Figure 11-3, 28.00 to 31.00 inHg) agree within 1.5 feet, and the standard-atmosphere table (Figure 11-2) agrees to its printed precision.
- Density altitude. The National Weather Service example the PHAK quotes (22.22 inHg, 80 °F, dewpoint 75 °F) gives 11,564 feet with the NWS formula; the exact humidity calculation used here lands within 30 feet of it.
Exact answers and quick estimates
Where pilots commonly use a rule of thumb, the result shows it next to the exact answer. Pressure altitude uses the standard-atmosphere relationship; the familiar 1,000 feet per inch of mercury is listed as a quick estimate. Density altitude inverts the standard atmosphere exactly; the 120 feet per degree Celsius rule is shown beside it. True airspeed accounts for compressibility and also shows the density-only value a mechanical E6B gives.
Directions, winds and units
Courses and headings are in degrees, with 360 for north. Winds are always the direction the wind blows from. Winds in METARs, TAFs and winds-aloft forecasts are relative to true north, while ATIS and tower winds are magnetic. Use the same reference as the course or runway you compare them with. Speeds are knots and distances nautical miles; temperature and pressure units switch with the buttons on each calculator, and your choice is remembered.
Questions pilots ask
Is this E6B calculator accurate enough for flight planning?
It uses exact standard-atmosphere and wind-triangle math and reproduces the FAA handbook examples described on this page. It is a planning and training aid, not FAA-approved equipment: check results against your aircraft's POH/AFM and official weather.
Can I use this E6B calculator on the FAA knowledge test?
No. FAA Order 8080.6H, which now holds the test-aid rules that were in the cancelled AC 60-11C, keeps portable phones and similar devices out of the testing area. Navigation computers and calculators directly related to the test are allowed, so bring a mechanical E6B or an electronic flight computer whose memory can be erased.
Why does my mechanical E6B give a slightly different answer?
A mechanical E6B is read by eye to about 1 percent, its altitude window uses the incompressible density method, and many pilots use rules of thumb such as 1,000 ft per inch of mercury. Where those differ from the exact answer, the result shows both so you can check your wheel work.
Are my numbers sent anywhere?
No. The calculations run in your browser. Your last inputs and unit choices are kept in this browser's local storage so they are there next time; nothing you type is sent to the site.