Navigation Planning
E6B Flight Computer
Use the E6B Flight Computer below to calculate wind correction angle and ground speed, solve time, speed, and distance problems, plan fuel burn and endurance, find true airspeed, determine winds aloft from known flight parameters, and correct for off-course deviation.
Usage Guide
How to use the online E6B flight computer?
Wind Triangle — wind correction angle and ground speed
To calculate wind correction angle and ground speed using the online E6B flight computer, follow the steps below:
- 1.Enter True Course in degrees.
- 2.Enter True Airspeed in knots.
- 3.Enter wind direction (FROM) in degrees and wind speed in knots.
- 4.The calculator returns Wind Correction Angle, True Heading, and Ground Speed.
- 5.Enter magnetic variation to convert True Heading to Magnetic Heading.
- 6.Enter compass deviation to convert Magnetic Heading to Compass Heading.
Time, Speed, and Distance
To solve a time, speed, or distance problem using the online E6B flight computer, follow the steps below:
- 1.Select the unit system: knots and nautical miles, mph and statute miles, or kph and kilometres.
- 2.Enter two of the three values: Time, Speed, or Distance. Leave the unknown field blank.
- 3.The calculator solves for the missing value. Time accepts HH:MM or decimal hours.
Fuel Planning — burn rate and endurance
To calculate fuel endurance using the online E6B flight computer, follow the steps below:
- 1.Enter fuel available in the selected unit.
- 2.Enter fuel burn rate in the same unit per hour.
- 3.Select the reserve mode: VFR day (30 minutes), VFR night (45 minutes), IFR (45 minutes plus alternate flight time), or custom.
- 4.The calculator returns total endurance and safe endurance after reserve deduction.
True Airspeed, Mach number, and density altitude
To calculate true airspeed using the online E6B flight computer, follow the steps below:
- 1.Enter Calibrated Airspeed (CAS) in knots.
- 2.Enter pressure altitude in feet.
- 3.Enter outside air temperature (OAT) in °C or °F.
- 4.The calculator returns True Airspeed, Mach number, speed of sound at altitude, ISA deviation, and density altitude.
Winds Aloft — find wind direction and speed from a known flight
To determine winds aloft from a completed flight leg using the online E6B flight computer, follow the steps below:
- 1.Enter True Course in degrees.
- 2.Enter True Heading in degrees.
- 3.Enter True Airspeed in knots.
- 4.Enter Ground Speed in knots.
- 5.The calculator returns wind direction, wind speed, headwind component, and crosswind component.
Off-Course Correction — regain track or fly direct to destination
To calculate an off-course correction using the online E6B flight computer, follow the steps below:
- 1.Enter distance flown in nautical miles.
- 2.Enter off-track error in nautical miles and select the direction of error (left or right).
- 3.The calculator returns the parallel track correction — the heading change to regain the original track.
- 4.Enter distance remaining to destination to receive the direct-to correction — a single heading change that intercepts the destination without returning to the original track.
E6B Basics
What is an E6B flight computer?
An E6B flight computer is a mechanical analog navigation device used in aviation to perform flight planning and in-flight calculations without electrical power. It allows pilots to calculate speed, time, distance, fuel, and wind correction. The E6B flight computer was invented by Philip Dalton in the 1930s.
The mechanical E6B flight computer has two sides. The front side calculates numbers. The back side solves wind navigation problems. Both sides support flight planning and in-flight calculations.
1. Calculator side (front)
The calculator side of the E6B uses a circular slide rule to perform mathematical and aviation calculations.
The outer scale displays fixed values for distance, speed, and volume. These include nautical miles, statute miles, gallons, and fuel flow rates.
The inner scale rotates to perform calculations. The pilot aligns values on both scales to solve multiplication, division, and unit conversion problems.
The calculator side solves:
- •Time, speed, and distance calculations
- •Fuel burn and endurance calculations
- •Unit conversions for weight, speed, and volume
The calculator side includes window scales. These windows calculate pressure altitude, density altitude, and true airspeed from input values such as temperature and calibrated airspeed.
2. Wind side (back)
The wind side of the E6B uses a compass rose and a wind grid to solve wind correction problems.
The compass rose displays 360 degrees for true course and wind direction.
The sliding grid represents aircraft airspeed and wind speed. The pilot positions the wind vector on the grid using the grommet as the reference point.
The wind side solves:
- •Wind Correction Angle (WCA)
- •Ground Speed (GS)
- •True Heading (TH) adjustment for wind drift
The wind side shows how wind changes aircraft track over the ground and how pilots correct heading to maintain course.
Online E6B flight computer
E6B apps, like the one on this page, replicate the calculation functions of a physical E6B flight computer in digital form. They compute the same navigation, wind, speed, and fuel calculations without requiring a mechanical slide rule.