Plug these deterministic inputs into the calculator to reproduce the numbers on the page: 120 additional orders captured per month, $28 average ticket, 30% food cost, $799 Fire It plan, $0 other monthly costs. Gross revenue is 120 × $28 = $3,360. Food cost is $3,360 × 0.30 = $1,008. Contribution margin is $3,360 − $1,008 = $2,352. Net after SaaS is $2,352 − $799 − $0 = $1,553. Payback in tickets is ceil($799 / ($28 × 0.70)) = 41 tickets, which is the count of incremental tickets the plan needs before the month is net-positive.
If you don't yet have a defensible "additional orders captured" number, start with the missed-call revenue calculator and use a conservative fraction — 40% to 60% — of the modeled lost orders. That's a floor, not a promise; a two-week pilot is still the only way to know for your specific catchment.