Instructions: This calculator may be used to calculate the maximum declination drift permissible during a drift align to maintain a polar axis alignment error no greater than the input value. For more information on the mathematical model behind this calculator see my article on the subject. Alignment Error: Enter the maximum tolerable alignment error in arcminutes. If you know arcminutes and arcseconds enter it as MM.SS and click "Convert MM.SS". Time: Enter the total time of the measurement in decimal minutes. If you know the seconds enter that number and click "Convert Secconds" If you know the minutes and seconds enter it as MM.SS and click "Convert MM.SS". Declination: Enter the declination of the drift star in decimal degrees. If you know the degrees, arcminutes, and arcseconds enter it in the form DDD.MMSS or DD.MM and click "Convert DDD.MMSS". Calculate: When you have entered and converted all your inputs to the proper units, click "Calculate." The Drift and Drift Rate will be calculated and displayed in the fields below.