Dead Reckoning is a means of calculating one’s current position or fix from a previously determined fix (these are usually checkpoints circled on the sectional chart). A flight computer can be used to calculate the time between these fixes and let the pilot know the exact time when the next checkpoint should be spotted. The course line drawn on the sectional chart is the True Course (TC), which will be different from the actual course flown using the magnetic compass. During the flight planning stage, the wind direction at the cruising altitude will need to be determined using the Winds and Temperatures Aloft (FB) weather product available on the aviationweather.gov website. The wind direction (referenced from true north) and speed can be found under the Forecasts section of the website. A flight computer such as an e6b can then be used to calculate the True Heading (TH) from the True Course (TC) drawn on the chart.

The TH is the direction the aircraft must be pointed to compensate for wind drift. The Wind Correction Angle (WCA) is the difference between the TC and the TH.  Since magnetic north is different from true north, the Magnetic Heading (MH) must be calculated by adding or subtracting the magnetic variation from the TH. Magnetic variation is depicted on sectional charts as dashed magenta lines called isogonic lines. Pilots should determine which isogonic line lies closest to the course line and then add or subtract that number to determine the MH. Finally, magnetic deviation, which is noted on the compass card in the aircraft, should be added or subtracted from the MH to determine the actual direction the aircraft will be pointed in flight—the Compass Heading (CH). Maintaining this heading should result in a track (the airplane's path over the ground) that closely follows the course line drawn on the sectional chart. Calculating the WCA on a flight computer like the e6b also produces the groundspeed, which can then be used to determine the total time en route and the time between checkpoints.