SEO ROI Calculator for Service Businesses

The Formula

SEO is an investment equation.

Revenue = (Search Volume * CTR * Conversion Rate * Close Rate * LTV)

1. The Variables

• Search Volume: How many people search "Emergency Plumber"? (e.g., 1,000/mo).
• CTR (Click Through Rate): Ranking #1 gets ~20-30%. (250 visitors).
• Conversion Rate: Website visit to Lead. ~5%. (12.5 leads).
• Close Rate: Lead to Sale. ~40%. (5 sales).
• LTV: Value of Sale. $500.

2. The Calculation

5 sales * $500 = $2,500 Revenue / Month.

• Cost of SEO: $1,000/mo.
• ROI: ($2,500 - $1,000) / $1,000 = 150% ROI.

3. The Compounding Factor

This calculation is for Month 1 of ranking. In Month 12, you still pay $1,000, but you might rank for 10 keywords. Revenue: $25,000. Cost: $1,000. ROI: 2,400%.

Conclusion

Use this logic to justify your budget. SEO is the only channel where the Cost per Acquisition (CPA) goes down over time.