How to calculate the real return on investment for AI subscriptions
2–4 minutes
In recent years, AI subscriptions have proliferated, with many professionals paying for multiple tools without knowing if their investment yields results. While an individual plan typically costs just a few dozen dollars per month—a seemingly small amount—it can become significant when accumulated over a year or across an entire team.
To assess the return on investment, it’s essential to look beyond the monthly fee. You need to measure how much time the tool saves, how much time is spent reviewing its output, and whether the final quality has improved.
The logic behind the calculation
The starting point is to compare the value of time saved with the total cost of the solution. The time saved is multiplied by the hourly rate of the person using the tool. For example, a professional earning R$60 per hour who saves five hours per month generates a gross gain of R$300.
However, the total cost extends beyond the monthly fee. To calculate the net gain, subtract the hours spent on review from the hours saved, multiply the result by the hourly rate, and then deduct subscription and implementation fees.
The four components of the analysis
Subscription and licenses
This includes the main plan, paid extensions, and additional licenses for other team members. For businesses, it’s also worth checking if there’s a charge based on usage volume.
Time saved and human review
Time savings aren’t automatic. A study by the NBER, conducted by researchers from Stanford and MIT with customer support agents, found an average productivity increase of 14%, with a greater effect among less experienced professionals.
Conversely, a 2025 study by the METR organization observed that experienced developers took more time to complete tasks with AI support than without it, partly due to the effort required to review the generated material. Therefore, review time should be factored into the calculation.
Implementation
This represents the initial cost of deploying the tool, including training, creating instruction models, integrating with systems, and making security adjustments. This cost is typically spread over 12 months to avoid distorting monthly analysis.
Impact on quality
An experiment by Harvard Business School with BCG consultants showed that, for tasks suitable for AI, the quality of deliverables improved significantly. In tasks outside the tool’s scope, users were more likely to make mistakes than those without AI. Measuring errors, rework, and customer satisfaction helps capture this effect.
Practical example
A marketing analyst pays R$110 per month for an AI tool to create reports. He saves 8 hours per month but spends 3 hours reviewing the content, leaving 5 net hours. At R$50 per hour, this equates to R$250.
After deducting the subscription fee, R$140 remains. If the initial training cost R$100 in work hours, spread over 12 months (about R$8 per month), the final monthly gain is approximately R$132.
How to test before renewing
A 30-day trial period is usually sufficient to evaluate the tool. During this time, the professional should time how long tasks take with and without the solution, record review time, and compare the quality of deliverables, preferably with feedback from a colleague or manager.
If the net gain is positive and quality remains the same or improves, the subscription is justified. If the return is low, options include switching plans, restricting use to tasks with proven benefits, or canceling. Repeating the test at each renewal prevents paying for features that are no longer useful.
