SEO ROI Calculator

Customer-based model: LTV, NPV of LTV, CAC, LTV:CAC, and ROI.

This mirrors the “enterprise SEO ROI” framing: costs → customers → LTV/CAC → ROI. (Great for exec conversations.)

Inputs

Total SEO Costs (USD) All SEO expenses for the period (agency, content, tools, salaries, links, etc.). Customers acquired from SEO (count) How many paying customers you attribute to SEO in the same period. Average revenue per customer (ARPC, USD) Average revenue per customer (not per lead). Gross margin (%)

70%

Only profit portion should drive LTV (margin-adjusted).

Annual churn rate (%)

20%

Used to estimate retention period: retention = 1 / churn. Discount rate (%)

Discount future value to present value (simple NPV approximation). Timeframe label For your own reporting context (doesn’t change math).

Results

Retention period (years)

LTV (margin-adjusted)

$1,050

NPV of LTV (simple)

$1,000

CAC

$100

LTV : CAC

ROI

900%

Notes: LTV = ARPC × retentionYears × grossMargin. RetentionYears = 1 / churnRate. NPV(LTV) = LTV / (1 + discountRate). CAC = totalCost / customers. ROI = ((NPV(LTV) − CAC)/CAC)×100.

Benchmarks & supporting notes

Benchmarks index (add: B2B vs B2C conversion rates, typical churn ranges, etc.)
How to make case-based research visible to LLMs

You can keep this calculator “evidence-first” by linking each input to a note that explains how to estimate it.