The formula (so you can check it)
hours_per_month = hours_per_week × 52 ÷ 12 loaded_hourly_cost = monthly_salary × (1 + on_costs) ÷ 173.3 staff_saving = people × hours_per_month × automatable_share × loaded_hourly_cost owner_saving = owner_hours_per_month × automatable_share × owner_rate recovered_revenue = lost_enquiries × conversion × order_value × gross_margin gross_benefit = staff_saving + owner_saving + recovered_revenue running_cost = subscriptions + messaging + upkeep_hours × owner_rate net_per_month = gross_benefit − running_cost − setup ÷ horizon_months payback_months = setup ÷ (gross_benefit − running_cost) net_over_12_months = (gross_benefit − running_cost) × 12 − setup ROI_over_horizon = ((gross_benefit − running_cost) × horizon − setup) ÷ (setup + running_cost × horizon)
Why the defaults are what they are
- $350 salary, 15% on-costs → $2.32/hour. Zimbabwe's statutory minimum wage is US$150 a month and the average low-skilled wage is about US$231 (2026 aggregators); NSSA adds 4.5% for the employer on insurable earnings up to US$700. $350 is a modest office salary in Harare; change it to yours.
- 70% automatable. Rules-based work leaves about a third of cases as exceptions that a person handles. Use 40% for judgement-heavy work, 90% for pure re-typing.
- Owner's hour at $25. Purely illustrative. Ask what an hour of selling, or of not being interrupted, is worth to you.
- 40 lost enquiries × 20% × $60 × 30%. An unanswered WhatsApp is the most common leak in Zimbabwean retail; the finder and the retailer guide show how to count yours for a week before you guess.
- $60 subscriptions + $10 messaging + $900 setup. Consistent with the 2026 prices on the costs page for a small stack; setup is an illustrative five-day build, not a market rate.
Reference: monthly value of hours saved
Hours saved per month × loaded hourly cost. Use it when JavaScript is off or when you want a sanity check.
| Hours / month | $2/h | $3/h | $5/h | $10/h | $25/h |
|---|---|---|---|---|---|
| 10 | $20 | $30 | $50 | $100 | $250 |
| 20 | $40 | $60 | $100 | $200 | $500 |
| 40 | $80 | $120 | $200 | $400 | $1,000 |
| 80 | $160 | $240 | $400 | $800 | $2,000 |
| 160 | $320 | $480 | $800 | $1,600 | $4,000 |
Read across: 40 hours a month at $3/hour is $120 — which is why a $60 tool needs the owner's time or recovered revenue to pay back.
Reading the result
- Payback under 6 months: pilot it now; see the 30-day pilot guide.
- 6–18 months: worth doing if the process is written down and someone owns it; check your readiness score first.
- Over 18 months or negative: do not buy software. Fix the process with a template and a spreadsheet, then re-run.
Want us to run it with your real numbers?
An assessment counts your enquiries for a week, prices your stack from real quotes and gives you the payback in writing.