Use the formula `=(New Value-Old Value)/Old Value`
Format the result cell as Percentage
To show absolute percentage difference, use `=ABS((New Value-Old Value)/Old Value)`
If Old Value is in A1 and New Value is in B1, use `=(B1-A1)/A1`
If you want the percentage change from B1 to A1, use `=(A1-B1)/B1`
To avoid errors when the old value is zero, use `=IF(A1=0,””, (B1-A1)/A1)`
To calculate percentage difference between two values, use `=ABS(A1-B1)/AVERAGE(A1,B1)`
Multiply by 100 only if the cell is not formatted as Percentage
Copy the formula down to apply it to other rows