NADOLSKYI | Deviation

Calculator app

Deviation

Enter observed compass deviations on the eight main headings. The app calculates A, B, C, D, and E coefficients and draws the deviation curve.

Observed deviation

Eight headings

Use degrees. West can be entered as negative values if that is how your worksheet records deviation.

N 0° NE 45° E 90° SE 135° S 180° SW 225° W 270° NW 315°

Fill all eight headings with valid numbers.

Result

Deviation model

δ = A + B sin H + C cos H + D sin 2H + E cos 2H

Deviation curve

Calculation table

Detailed values

Heading	Course	δ	½(I+II)	½(I-II)