Prepare data
- Field names in the first row, no merged cells, no blank rows;
- One data type per column;
- Press Ctrl+T to make it a table so the pivot can grow.
Build it
- Insert → PivotTable, pick the source and destination;
- Drag dimensions to Rows and measures to Values;
- Set the value field to sum, count or average.
Next level
- Group dates by month or quarter;
- Add calculated fields for ratios such as margin;
- Insert slicers for dashboard-style filtering.