SEO Campaign Payback Calculator

What this number means

Payback month is the first month whose cumulative revenue covers the campaign cost. With the defaults — $36,000 cost, $2,000/month starting revenue growing 10% monthly — cumulative revenue passes $36,000 in month 11 ($37,062).

Total profit at horizon is what the campaign earns over the full 24 months minus its cost: $176,994 − $36,000 = $140,994. The cashflow chart shows the journey: underwater for 10 months, then compounding hard. If the line never crosses zero inside your horizon, the tool says so honestly: beyond the horizon.

The formula

In plain English: monthly revenue compounds at your growth rate; each month's revenue is added to a running total; the payback month is when that running total first covers the campaign cost.

• Revenue in month m = Starting revenue x (1 + growth)^(m−1)
• Cumulative revenue at month m = sum of monthly revenues, months 1..m
• Payback month = first m where cumulative revenue ≥ campaign cost
• Total profit at horizon = Cumulative revenue at horizon − campaign cost
• No payback inside the horizon is reported as "beyond the horizon", not hidden

Worked example

A company invests $36,000 in a year of SEO. The campaign starts producing $2,000/month, growing 10% monthly as rankings compound.

• Month 10 cumulative: $31,875 — still underwater
• Month 11 cumulative: $37,062 — payback
• Month 24 cumulative: $176,994 — $140,994 profit

Drop growth to 5% and payback slides to month 14; at 0% growth the campaign never compounds and payback lands at month 18 ($2,000 × 18 = $36,000). The growth assumption is doing most of the work — which is exactly why it deserves its own slider.

Assumptions and limitations

• Compounding is the optimistic engine. Real SEO revenue rarely compounds smoothly at a fixed rate — algorithm updates, seasonality, and competition cause plateaus and dips this model does not show.
• Revenue attribution is assumed. The starting revenue figure must genuinely be SEO-attributed; mixing in brand or paid revenue inflates payback.
• Costs are a lump sum. Ongoing monthly spend during the campaign is folded into the total; the model does not time costs against revenue month by month.
• No discounting. A dollar in month 24 is treated the same as a dollar in month 1; no time value of money is applied.
• All figures are planning estimates.