83% of marketing leaders say proving ROI is their top priority. Yet only 36% can actually measure it accurately.
Maths isn’t the problem.
It’s the scattered data, hidden costs, and the boss who wants instant answers, as well as the finance department that needs to know the reasoning behind an increased budget for events. This guide gives you a practical framework for marketing ROI that actually works and (even better) a calculator to prove that it does.
47% of marketers struggle with multi-touch attribution. Did that customer convert because of your email, blog post, social ad, or all three?
Then there’s the time lag. A blog post published six months ago generated a sale today. The freelancer costs you forgot. The hours spent in meetings about the campaign.
54% of marketers feel marketing is poorly understood in their organisation. No wonder the pressure to prove value feels never-ending.
ROI = (Revenue – Marketing Cost) / Marketing Cost × 100
Looks simple, doesn’t it? The problem is what people leave out of “marketing cost”.
You run a LinkedIn ad campaign. £500 on ads. £2,500 in sales.
Quick calculation: (£2,500 – £500) / £500 × 100 = 400% ROI
But what about the 4 hours you spent setting it up (£200 of your time), the copywriter (£150), your ads tool (£50), and sales team time (£300)?
Actual cost: £1,200 Real ROI: (£2,500 – £1,200) / £1,200 × 100 = 108% ROI
Still positive, but half what you thought.
Search Engine Land suggests:
But context matters. Email marketing should hit £36-£40 return per pound spent (3,600% ROI). Brand campaigns might only show £1.87 immediate return but £4.11 long-term.
The channel and timeframe matter. Which is why you need consistent measurement.
ROI = (Total Revenue – Organic Sales – Marketing Costs) / Marketing Costs × 100
Not every sale originated from your marketing efforts. You run an email campaign. Total sales that month: £5,000. But £2,000 would have happened anyway.
Your campaign generated £3,000 in additional revenue.
Spent £500: (£3,000 – £500) / £500 × 100 = 500% ROI
Much more honest than claiming credit for all £5,000.
Organic sales are the revenue you’d have made without this specific campaign. Think of it as your baseline.
Include as organic:
Don’t include as organic:
The easiest way? Look at your average monthly revenue before the campaign started. That’s roughly your organic baseline.
Marketing costs include all expenses incurred to make this campaign happen. Not just the obvious ad spend.
Always include:
Often forgotten:
If you hadn’t spent that money or time on this campaign, include it in your costs.
“Generate 50 email signups from this LinkedIn campaign” beats “increase brand awareness”.
Add them to every link. Thirty seconds of work saves hours of confusion.
One marketer tracked 12 touchpoints over six months before a £50,000 purchase. Early content mattered more than last-click attribution suggested.
The CIM suggests three sections: successes, challenges, and actionable recommendations.
Brand awareness, community building, and thought leadership. These have value, but calculating precise ROI often doesn’t make sense.
AgencyAnalytics notes that organic social is a branding activity. Track engagement, mentions, and sentiment instead.
Not everything needs an ROI percentage. But everything needs measurable outcomes.
Perfect ROI calculation is often impossible. You’ll never capture every touchpoint or know if someone would have bought anyway.
That’s fine. The goal isn’t perfection. It’s a consistent framework and benchmarks for measuring what works for your business.
64% of companies base future budgets on past ROI. Even imperfect measurement is better than decisions based on hunches.
Start where you are. Track what you can. Improve over time.
