
How to calculate ROI for a campaign?
Key Facts
- ["AI voice agents cost roughly $0.11 per minute, making a 4-minute call $0.44 vs $2.70-$5.60 for human-handled calls (6-13x savings)", "https://www.retellai.com/blog/roi-ai-voice-agents-cost-model"], ["Cost per resolution exposes what cost per contact conceals—AI might deflect 85% of calls but only resolve 60%, meaning 25% of callers gained nothing", "https://www.usehaven.ai/post/ai-call-center-pricing-benchmarks-cost-guide"], ["My AI Call Center pricing starts at 9¢ per connected minute, tiered by volume and locked before launch", "Business Context"], ["Recovered opportunity cost formula: N × M × E (call volume × missed-call rate × revenue per converted call)", "https://www.retellai.com/blog/roi-ai-voice-agents-cost-model"], ["Second-year ROI for AI call centers typically runs 40-60% higher than year one as scripts and lists refine", "https://pathors.com/en/blog/ai-call-center-roi-guide"], ["Industry data shows 20-30% of inbound business calls go unanswered or abandoned—every one is walked revenue", "https://www.retellai.com/blog/roi-ai-voice-agents-cost-model"], ["Human agent fully-loaded cost is $29–$42 per hour once benefits, attrition, QA, and management overhead are counted", "https://www.retellai.com/blog/roi-ai-voice-agents-cost-model"]]
Why Traditional ROI Metrics Fail for Outbound Campaigns
Most ROI calculations for outbound campaigns are wrong before the first call is even dialed. The problem isn't bad math — it's measuring the wrong things.
Cost-per-call hides more than it reveals. A campaign can look cheap at $2.70 per contact while quietly bleeding money elsewhere. Human call agents cost far more than their wage: one cost analysis puts the fully loaded rate at $29–$42 per hour once benefits, attrition, QA, and management overhead are counted. Turnover makes it worse — industry data shows agent attrition of 30–45% annually, with replacement costs of $2,000–$10,000 per agent. For a 100-agent team, that's $500K–$900K per year that never appears on a per-call invoice.
Technology costs distort the picture too. A 2025 IDC analysis found actual AI project total cost of ownership runs 42% higher than budgeted, mostly from underestimated integration and maintenance. And missed connections — 20–30% of calls going unanswered — represent recovered revenue that per-call metrics simply ignore.
The deeper failure is measuring activity instead of outcomes:
- A "connected call" tells you nothing — the average connect rate is just 16.6%, and it takes roughly 8 attempts to reach anyone.
- Deflection isn't resolution. An AI system might handle 85% of calls but only truly resolve 60% — meaning 25% of contacts gave up or called back, and you paid for nothing.
- Per-interaction pricing bills you even when the call fails to achieve its goal; per-outcome pricing only counts when the problem is actually solved.
As one pricing guide puts it plainly: "Cost per resolution exposes what cost per contact conceals." That's why resolution rate benchmarks — not call volume — are now treated as the single most important variable in calculating return.
This is why My AI Call Center reports campaigns by disposition — confirmed, qualified, renewed, opted out — rather than raw dials. A structured campaign with one clear goal lets you divide total cost by outcomes that actually happened, which is the only number worth defending.
Ready to see what resolution-based ROI looks like on your lists? Plan a managed outbound calling campaign against your approved, permissioned contacts — calling starts at 9¢ per connected minute, quoted in full before launch.
The Resolution-Based ROI Framework: Cost Savings + Opportunity Recovery
Most ROI calculators overpromise and underdeliver. The honest version, according to one cost-model analysis, is simpler and defensible: two formulas, five inputs, one number you can stand behind.
Part one: direct cost savings. The formula is N × T × R × (Cₕ − Cₐ) — call volume, times average handle time, times containment rate, times the gap between your fully-loaded human cost per minute and your AI cost per minute. The key word is "fully-loaded": wages are the smallest line item, and benefits, attrition, QA, training, and management overhead roughly double the base wage by the time it hits your P&L.
The benchmarks make the gap hard to ignore. AI voice agents operate at roughly $0.11 per minute, putting a typical 4-minute call at $0.44 versus $2.70–$5.60 for a human-handled call — a 6–13x differential before counting anything else. Managed services like My AI Call Center fit into this formula at the Cₐ position, with calling starting at 9¢ per connected minute, tiered by volume and locked before launch.
Part two: recovered opportunity cost. This is where the hidden ROI lives. The formula is N × M × E — call volume, times missed-call rate, times average revenue per converted call. Industry data points to 20–30% of inbound business calls going unanswered or abandoned, and every one of those is revenue that walked. In one worked example at 20,000 calls per month, direct savings reached $28,600 monthly while recovered revenue added $200,000 — the opportunity recovery dwarfed the labor savings.
To run the model on your own campaign, gather five inputs:
- N — monthly call volume on the campaign list
- T — average handle time per call
- Cₕ and Cₐ — fully-loaded human cost per minute versus AI cost per minute
- M — your current missed-call or non-response rate
- E — average revenue per converted call
One caution: the industry is shifting from cost-per-call to cost-per-resolution, and that distinction matters enormously. An AI system might deflect 85% of calls but only resolve 60%, meaning 25% of callers gave up and called back — you paid for the interaction and gained nothing. That's why tracking actual outcomes (confirmed, qualified, renewed) is critical to accuracy. A campaign report that shows disposition codes per call gives you the resolution data this model depends on — no invented numbers, just what actually happened.
Applying the Model: Step-by-Step Calculation Using Real Call Outcomes
Formulas are easy; the hard part is knowing which numbers to trust. The most defensible ROI calculations use real call outcomes—not projected conversions—to build the picture from the ground up.
Step 1: Define the outcome before the campaign launches. Every campaign should have one clear goal: confirm, qualify, remind, or renew. This matters because research on AI ROI shows that resolution rate—not call volume or deflection—is the single most important variable in any ROI calculation. A campaign that generates 1,000 connected minutes but zero confirmed appointments has a different ROI story than one with 200 confirmed bookings.
Step 2: Capture actual outcomes with disposition codes. A managed service like My AI Call Center reports named outcomes per contact: confirmed, qualified, renewed, opted out, or no answer. These codes become your ROI inputs. Industry benchmarks help you sanity-check the results: the average connect rate is 16.6% of dials, and it takes roughly 8 attempts to reach a prospect. If your approved list connects at 30%+, your list quality is well above market norms.
Step 3: Apply the fully-loaded cost formula. Total campaign cost is:
- (Connected minutes × per-minute rate) — with managed calling starting at 9¢ per connected minute, locked before launch
- One-time campaign setup fee, quoted upfront
- Flat monthly management fee, quoted upfront
This transparency matters. Pricing research warns that advertised rates often hide integration and API costs—many platforms quoting 5¢ per minute actually cost 11-24¢ once all layers are included. An all-in rate, agreed before launch, keeps your ROI math honest.
Step 4: Factor in opportunity cost recovery. The biggest ROI lever is often not labor savings but recovered revenue. One cost model frames it simply: multiply missed-call volume by average revenue per converted call. Since 20-30% of inbound business calls go unanswered, every reactivation or reminder campaign that recovers even a fraction of that gap adds a revenue line most ROI spreadsheets miss.
Step 5: Benchmark and iterate. Compare your cost per outcome against human alternatives—human-handled calls run $2.70-$5.60 versus AI-handled interactions at $0.25-$0.80. Then track improvement: second-year ROI typically runs 40-60% higher than year one as scripts and lists refine, according to client data from AI call center deployments.
The result is one number you can defend: total campaign cost divided by the value of outcomes actually delivered, grounded in what happened rather than what was promised.
Frequently Asked Questions
Why is cost-per-call the wrong way to measure campaign ROI?
What's the actual formula for calculating ROI on an outbound campaign?
How much does a human call agent really cost compared to AI?
What call outcomes should I track to know if my campaign actually worked?
Why do advertised AI calling rates often end up costing more?
How long until an AI calling campaign pays for itself?
One Number You Can Defend
The math only works when you measure what actually happened. Traditional cost-per-call metrics hide the real story: fully-loaded human costs of $29–$42 per hour, turnover that quietly drains $500K–$900K per year from a 100-agent team, and deflection numbers that mask unresolved calls you already paid for. The defensible approach is simpler: define one clear outcome before launch, track real dispositions — confirmed, qualified, renewed — and divide total cost by outcomes that actually occurred. Then add the hidden ROI: recovered revenue from the 20–30% of calls that typically go unanswered, which cost modeling shows can dwarf direct labor savings. That's how My AI Call Center reports every campaign — real disposition codes, an all-in rate locked before launch, no invented numbers. If you want to see what resolution-based ROI looks like on your own approved, permissioned lists, plan a managed campaign with calling starting at 9¢ per connected minute — quoted in full before anything dials.