How to Analyze Year-over-Year Sales in Excel

1. Prepare the source and scope

Import sales.csv into a new worksheet with headers in row 1. Leave the source columns in their original order for the formulas below. Review the data dictionary before choosing the reporting period. Keep identifiers as text and convert numeric columns explicitly. Save a working copy so you can return to the original fixture.

2. Build the calculation

Compare the same twelve months in each year. Calculate current revenue divided by prior revenue minus one, then format as a percentage.

=SUM(D14:D25)/SUM(D2:D13)-1

3. Reconcile and interpret the output

The expected check is annual revenue growth: 18.1818 percent. The increase comes from a 3,000 uplift in each corresponding month. Compare complete periods with the same currency and scope. If your result differs, inspect the selected rows, data types and date filters before changing the formula. Percentage formulas return decimal ratios; apply Percentage formatting rather than multiplying the cell value twice.

4. Adapt the workflow to a recurring report

Replace the sample with a copy of your own source, retaining the same column meanings and units. Extend bounded ranges to include new rows, refresh PivotTables where used, and compare the result to an independent source total. Record the reporting period and any exclusions beside the output. If prior revenue is zero, show growth as unavailable rather than dividing by zero.