What Is Return on Investment (ROI)?
What is return on investment? It is the ratio of net gain to the cost of an investment, expressed as a percentage, used to evaluate whether the benefit of an action justified its expense. The formula is simple; the hard part is defining what counts as gain and what counts as cost.
Calculate ROI from your spend and revenue data and compare it across campaigns, projects, or time periods
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| Date |
| Campaign |
| Spend |
| Revenue |
| Net Gain |
| ROI % |
| Channel |
| Product |
| Conversions |
| Cost Per Conversion |
What usually goes wrong with it
ROI calculations use inconsistent cost definitions
Some teams include only direct ad spend in the denominator; others add agency fees, creative costs, and tool subscriptions. Without a consistent definition, comparisons across campaigns or quarters mean different things.
DataMimi Datamimi flags when the cost column contains different cost types across rows — direct spend in some, total budget in others — and asks which definition to use before calculating.
Revenue attribution is unclear with multi-touch customers
A customer who clicked a paid ad, then visited via organic, then converted from email gets attributed differently depending on whether the model is first-touch, last-touch, or linear.
DataMimi It notes the attribution model recorded in the Channel column header and applies it consistently rather than mixing models mid-calculation.
Time period mismatches make the metric misleading
A campaign that spent $50K in Q1 and generated revenue through Q3 looks unprofitable in a Q1-only view. Matching cost period to full revenue collection requires tracking individual conversion dates.
DataMimi Datamimi aligns cost and revenue rows by campaign ID and date range, so Q1 costs match revenue rows through Q3 if the campaign column connects them.
Common questions
What is return on investment as a formula?
ROI = (Net Gain ÷ Cost of Investment) × 100. If you spent $10,000 on a campaign and generated $30,000 in revenue, net gain is $20,000 and the result is 200%.
What is a good return on investment for marketing?
A common benchmark is 4:1 (400%) for marketing spend. Email marketing averages higher; paid search averages 200–400%. Your own baseline over time is more useful than an industry average.
What is the difference between ROI and ROAS?
ROAS (return on ad spend) measures revenue divided by ad spend only, without subtracting costs. ROI measures net gain divided by total costs, including COGS, fulfilment, and overhead. ROAS is always higher than ROI for the same campaign.
How do I calculate return on investment in Excel?
=(Revenue−Cost)/Cost in a helper column. Format as Percentage. For multiple campaigns, add this formula to each row, then sort descending to find the highest performers.
What does Datamimi cost?
Free: $0/month, 40 credits, no credit card required. Lite: $9/month, 400 credits. Starter: $24/month, 1,500 credits, up to 3 simultaneous files. Pro: $59/month, 5,000 credits with rollover. Team: $199/month, 20,000 credits, 5 users.
Try it with your own file
DataMimi reads the file you actually have — merged cells, headers below row one, totals pasted at the bottom — and shows which rows and columns every number came from.
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