AI calling ROI calculator: a formula you can run in a spreadsheet

An AI calling ROI calculator does not need to be complicated. You need about eight inputs, five lines of arithmetic and the discipline to use your own numbers instead of optimistic ones. This page gives you the formula, a worked example with illustrative figures and the checks that stop you fooling yourself.

For the thinking behind it, see AI voice agent ROI. For a related measure, the cost per booked meeting calculator is a useful companion.

The inputs

Collect these before you start. Use real data where you have it, and say "assumption" where you do not.

Input	Symbol	Where it comes from
Contacts called	C	Your list size
Answer rate	A	Past campaigns, or a pilot
Qualified rate (of answered)	Q	Your definition of qualified
Booked rate (of qualified)	B	Calendar data
Show rate (of booked)	S	Calendar data
Close rate (of shows)	W	Sales records
Average deal value	V	Sales records
Total programme cost	T	See cost section below

The AI calling ROI formula

Answered      = C x A
Qualified     = Answered x Q
Booked        = Qualified x B
Showed        = Booked x S
Won           = Showed x W
Revenue       = Won x V
ROI           = (Revenue - T) / T
Cost per meeting = T / Booked
Cost per win     = T / Won

Use gross margin instead of revenue if you want a stricter test: replace V with the profit per deal.

Worked example (illustrative)

These numbers are made up to show the method. Replace them.

Step	Calculation	Result
Contacts called		1,000
Answered	1,000 x 30%	300
Qualified	300 x 30%	90
Booked	90 x 40%	36
Showed	36 x 70%	about 25
Won	25 x 20%	5
Revenue	5 x $2,000	$10,000
Total cost	see below	$1,500
ROI	(10,000 - 1,500) / 1,500	about 5.7x
Cost per booked meeting	1,500 / 36	about $42
Cost per win	1,500 / 5	$300

An ROI of 5.7x here means every dollar spent returned about $5.70 in extra profit-before-other-costs. It says nothing about your business until you replace the inputs.

What goes into total cost

Be generous when counting costs.

Cost item	Notes
Platform plan	Purple Voice is Free, Basic at $19 a month, Pro at $299 a month, or Enterprise by quote
Phone number rental	Billed by your telephony provider, not Purple Voice
Call and AI usage	Billed by the providers for minutes and AI usage
List cost	Buying or cleaning contact data
Your time	Setup, test calls, transcript review, prompt changes
Human follow-up	Cost of the people who take the booked meetings

In the example above, $1,500 might be made up of plan fees, provider usage, list costs and a few hours of review. The split is not important; including all of them is.

Check your sensitivity

Change one input at a time and see how much the result moves.

Scenario	Change	Effect on wins
Answer rate falls from 30% to 20%	Fewer conversations	Wins fall by a third
Booked rate rises from 40% to 50%	Better prompt and offer	Wins rise by a quarter
Close rate falls from 20% to 10%	Weaker meetings	Wins halve

Usually the later steps, show rate and close rate, move the answer most. If your booked meetings do not turn into deals, a better dialler will not fix the ROI.

Rules of thumb for honest modelling

• Use your lowest believable answer rate, not the best campaign you ever ran.
• Count only meetings that would not have happened anyway.
• Do not include the value of deals that were already in your pipeline.
• Include your own time at a realistic hourly rate.
• Re-run the sheet after the pilot with real numbers.

If you are planning a test, the 30-day pilot plan lays out how to collect them.

Spreadsheet layout

Put inputs in one column (C through V), costs in another, and the funnel in a third that references them. Then add a small table of three scenarios (pessimistic, expected, optimistic) so you can see the range, not just one number.

Try it

You can find your real inputs cheaply: run a small campaign on the Free plan, which includes one agent, one campaign of up to 100 contacts and 100 minutes a month, with no card. Insights and call summaries then give you answer, qualified and booked rates to drop into the sheet. Start at voice.purplerocket.co.