AI Receptionist ROI: A Worked Calculation

AI receptionist ROI comes down to one comparison: the value of calls the AI handles that would otherwise be missed or cost more to answer, against what the AI costs. To calculate it, pull a month of call data, count the calls the AI would take, estimate how many of those turn into revenue, and subtract the AI cost. The worked example below uses published prices and clearly labeled example inputs; replace them with your own numbers.

Step 1: Count the calls the AI would handle

From your phone system's call log for the last 30 to 90 days, count:

Call type	Where to find it
Missed calls during business hours	Missed or unanswered calls
After-hours calls	Calls outside your business hours
Calls that went to voicemail	Voicemail count
Voicemails never returned	Compare voicemails to callbacks
Routine calls staff answered (hours, directions, status)	Sample and estimate

Only count calls the AI would actually take based on how you'll set it up. If the AI answers only after hours, ignore business-hours misses.

Step 2: Estimate minutes and AI cost

Measure average call length for these call types, or use your overall average as a starting point. Then:

AI minutes per month = calls handled × average minutes per call

Add a buffer, since per-call rounding increases billed minutes. See estimating AI receptionist minutes.

Published pricing for comparison, checked October 2026:

Option	Published price	Notes
Callata AI agents	$0.25 per minute, prepaid	Phone system is $99/month separately (5 users included)
RingCentral AI Receptionist	$49/month standalone (or $39 add-on) with 100 minutes; $0.50/minute after	Billed in 30-second increments
Ruby (human receptionists)	$250/month for 50 minutes up to $1,725 for 500	Live people
Smith.ai (human receptionists)	$300/month for 30 calls; $11.50 per extra call on that plan	Per call, not per minute

Step 3: Estimate the value of a handled call

This is where most ROI estimates go wrong. Not every missed call is a lost customer. Many callers try again, leave a voicemail, or weren't buying. Build the value from three inputs you know:

1. Share of handled calls that are real opportunities (new customers or bookings), from your call log sample.
2. Your close rate on those opportunities when someone follows up promptly.
3. Average value of a new job or booking (first job, or a conservative lifetime value).

Monthly revenue recovered = opportunity calls × close rate × average value

Count only calls that would have been lost without the AI. If you're replacing voicemail, estimate how many voicemail callers never leave a message or never get reached. Pew Research found that most Americans don't answer calls from unknown numbers, which is one reason callbacks to missed callers often fail.

Step 4: Add staff time saved

If the AI takes routine calls your team answers today, that time has value:

Staff hours saved = routine calls moved to AI × minutes per call ÷ 60

Value it at the loaded hourly cost of the person who'd answer. For reference, the Bureau of Labor Statistics reports a 2025 median wage for receptionists of $18.27 per hour, before taxes and benefits.

Be careful here: saved time only becomes savings if it goes to other productive work or reduces paid hours.

Step 5: Put it together

ROI = (revenue recovered × margin + staff time value − AI cost) ÷ AI cost

Use gross margin, not revenue, so the result reflects profit.

Worked example (example inputs, not benchmarks)

A two-truck plumbing company sets up an AI agent for after-hours and overflow calls. Its own call log shows:

Input	Example value
After-hours and overflow calls per month	140
Average AI call length	2.5 minutes
Billed minutes (rounded up per call, about 3 each)	420
Share that are real service requests	35% → 49 calls
Close rate when followed up next morning	40% → about 20 jobs
Share of those jobs that would have been lost without AI	50% → 10 jobs
Average job value	$350
Gross margin	45%

AI cost: 420 minutes × $0.25 = $105

Recovered gross profit: 10 jobs × $350 × 45% = $1,575

ROI: ($1,575 − $105) ÷ $105 ≈ 14×

Now stress-test it. If only 20% of those jobs would truly have been lost, recovered profit falls to $630 and ROI to about 5×. If average calls run 4 minutes, AI cost rises to about $170. The conclusion here holds across the range, but your inputs may produce a different answer. That's the point of running it.

Same volume, other pricing models

At 420 minutes per month:

Option	Monthly cost for 420 minutes
Callata AI minutes	$105 (plus the $99 phone plan you'd use anyway)
RingCentral AI Receptionist standalone	$49 + 320 × $0.50 = $209
Ruby 500-minute plan	$1,725 (human receptionists)

Human services cost more because people handle nuance, emotion and exceptions better. Many businesses use AI for routine and after-hours calls and people for the rest. See AI receptionist vs answering service cost.

When ROI is likely to be low

An AI receptionist isn't a good investment for every business. The numbers tend to come out poorly when:

• You rarely miss calls. If staff answer almost everything and after-hours calls are rare, there's little to recover.
• Each call needs judgment. If most calls involve negotiation, diagnosis or sensitive conversations, the AI will mostly take messages, which voicemail with transcription may handle well enough.
• Leads aren't followed up. Captured leads that sit for days lose value quickly.
• Average job value is small and callers are price shoppers. Recovered calls may not convert at a rate that covers the cost.

In those cases, cheaper fixes (better voicemail, a missed-call text, adjusted staffing at peak hours) may give a better return.

Costs people forget

• Setup time: writing instructions and facts, testing. A few hours up front.
• Review time: 30 minutes a week reading transcripts. See reviewing AI agent conversations.
• Follow-up: the AI captures leads; someone still has to call them back.
• Carrier texting registration, if the AI texts.

Measure after launch

Your ROI estimate is a hypothesis. After 60 days, compare:

• Actual AI minutes and cost vs estimate.
• Opportunity calls the AI captured.
• Jobs booked from AI-captured calls (tag them).
• Follow-up speed on AI messages.

See AI agent performance metrics.

Running the numbers with Callata

Callata's AI agents can answer after hours, pick up when nobody answers during business hours, reply to texts, and answer a number directly. Minutes are $0.25 each, sold in prepaid packs of 60 ($15), 250 ($62.50) and 1,000 ($250), and counted per conversation, rounded up to the minute. Each AI text reply uses a quarter minute. The phone system itself, with call recording, AI summaries and voicemail transcription, is $99 per month for five users, plus $20 for each additional user. Start with Callata.