We know you're busy so there's a basic way to measure and report PPC ROI. In short, it's that formula, but the full explanation is below the title image.
How To Measure PPC ROI
We are concerned with bottom line impact, here.
As long as you can isolate the revenue generated by conversions from your PPC campaign, you can use this formula to quickly work out your PPC ROI percentage.
Remember to make sure your Revenue includes only conversions arising from the PPC campaign.
It's important to define the Cost item when reporting to your bosses too; is it the cost of the campaign solely in terms of Ad Spend? Or are you including product and costs too for a full investment cost?