The disclosure discloses a printer including a memory storing computer-executable instructions. In an index value detecting process, pulse count index values are detected. In a remaining amount determining process, first process, second process, third process, and fourth process are executed. In the first process, an Nth determination object value is calculated from an Nth and an N+1th pulse count index values. In the second process, an average value is calculated from a plurality of successive pulse count index values in a range including a latest value that is an Nth pulse count index value when N is an even number or is an (N−1)th pulse count index value when N is an odd number of three or more. In the third process, a remaining amount rank corresponding to the Nth determination object value is determined. In the fourth process, a rank display corresponding to the remaining amount rank is performed.