Tips & Tricks 41 – I have data for many years but I want the sum for only last 12 months

Let's assume that your data is aligned like this and you want to have sum only for last 12 months. This should take care of if future entries are done. Hence, if Jun data is entered, sum up has to start from Jun month. –

Use this formula –

=IFERROR(SUM(OFFSET(INDIRECT("$B"&COUNTA($A:$A)),0,0,IF(COUNTA($A:$A)-12>0,-12,-COUNTA($A:$A)+1),1)),"")

Note – If you have only one column say B, replace $A with $B. (If only A, replace $B with $A)