The ROI Math Behind Every Marketing Campaign
Stop guessing whether a campaign 'felt' worth it. Here's the one formula that settles it every time.
A campaign that "feels" successful is a campaign you can't defend at budget review. The fix is embarrassingly simple: write down two numbers and do one division.
The only formula you need
ROI % = (Total Return − Investment) ÷ Investment × 100
That's it. Everything else — attribution models, dashboards, fancy reporting — is flavor. If you spent $500 and generated $2,400 in revenue, your ROI is:
($2,400 − $500) ÷ $500 × 100 = 380%
Why annualized ROI matters
A 20% ROI in one month is far more impressive than a 20% ROI in a year. To compare apples to apples, normalize by time:
Annualized ROI = (1 + ROI/100)^(12 / months) − 1
Use our ROI Calculator — it does the monthly and annualized math side by side, so you never have to reach for a spreadsheet again.
The trap of counting revenue, not profit
The most common mistake in ROI math is comparing spend against revenue instead of profit. If your product has a 60% margin, then:
| Metric | Value |
|---|---|
| Ad spend | $1,000 |
| Revenue generated | $3,000 |
| Gross profit (60%) | $1,800 |
| True ROI | 80% |
That looks very different from the "300% ROI" your ads dashboard proudly displayed. Always subtract the cost of goods before you celebrate.
Set your thresholds before you launch
Decide in advance what "good" means so you don't rationalize afterwards:
- ›Below 0% — you're losing money; kill it or restructure it
- ›0–100% — positive but possibly better than the alternative
- ›100%+ — worth doubling down
- ›300%+ — exceptional, but ask yourself why before scaling blindly
One paragraph of advice
Track every campaign in the same place, using the same formula, every single time. It won't make marketing glamorous, but it will make your decisions defensible. And when a stakeholder asks "was it worth it?", you'll have a number instead of a shrug.
Run the numbers before your next launch: ROI Calculator.