Sales (₹112-151 lakh) and margin (30-37%) on one chart are unreadable with one axis: the margin line sits flat at the bottom. A secondary axis gives each its own scale.
Select the month, sales and margin columns > Insert > Combo chart > Clustered Column – Line on Secondary Axis.
Or change one series: right-click margin > Change Series Chart Type > Line, tick Secondary Axis.
Label both axes (Chart Elements > Axis Titles): “₹ lakh” and “Gross margin %”.
The finished example has sales as columns on axis 1 and margin as a line with markers on axis 2: November is the peak for both.
⚠️ Two axes can be made to show any story by changing their minimums. Start the column axis at 0, and set the % axis to a sensible range (e.g. 25%-40%) and say so in the title.
💡 If the two measures share units (sales vs target), don’t use a secondary axis; put them on the same one.
Practice
The practice workbook has the data and the helper formulas behind the chart (with automatic checks). Build the chart yourself, then open the finished examples file to compare. Excel built those charts and we checked their types and series.
