SEO ROI calculator, with the formula on the page.
Enter today's organic traffic, where you expect it to be, your conversion rate, deal value and monthly cost. You get the extra return, the ROI and the month it pays back, and every step of the arithmetic is visible.
By Mike Cecconello · Updated September 25, 2026
SEO ROI calculator
Runs in your browser. Nothing you paste is sent anywhere.
The numbers above are an example to show the arithmetic, not typical figures. Replace every one with yours. Leave gross margin at 100% to measure revenue, or set it to measure profit.
The formula
extra sessions in month m = (target − now) × m ÷ months
extra return in month m = extra sessions × conversion rate × order value × margin
ROI = (total extra return − total SEO cost) ÷ total SEO cost
Growth is assumed to be a straight line from now to the target. Only the sessions above today’s are credited to the spend, because you would have had today’s traffic anyway. Payback is the first month where cumulative extra return covers cumulative cost.
Month by month
What you can do with it
- Sanity-check a proposal before sending it to a client
- Work out how much traffic growth a retainer needs to pay for itself
- Show a finance team the assumption behind an SEO budget
- Compare a short and a long horizon for the same spend
How it works, step by step
- 1
Take today's organic sessions from analytics
Use a recent monthly average, not a single good month. Seasonal businesses should compare against the same month last year.
- 2
Set a target you can defend
This is the input that decides the answer, so base it on something: the traffic of the keywords you plan to target, or what a comparable page already earns. A target picked to make the ROI look good is the most common flaw in these models.
- 3
Use your own conversion rate and value
Organic visitors often convert differently from paid ones, so use the organic figure if you have it. For lead generation, multiply the lead rate by your close rate to get a deal rate.
- 4
Add margin if you want profit, not revenue
Leave gross margin at 100% to see a revenue ROI. Set it to your real margin to see whether the extra revenue actually covers the cost.
- 5
Read the payback month, then the verdict
Payback is the first month cumulative extra return covers cumulative cost. The verdict line also shows how many extra sessions a month the cost needs to break even.
The model, in one paragraph
Traffic grows in a straight line from where it is today to your target over the months you choose. Each month, the sessions above today’s level are multiplied by your conversion rate, your average order or deal value and your margin. That is the month’s extra return. Cost is your monthly spend. ROI is total extra return minus total cost, divided by total cost. Payback is the first month the running total of return catches the running total of cost.
The formula is printed under the result, and the month-by-month table shows every row, so anyone who disagrees with the answer can point at the input they disagree with.
What the calculator cannot know
- Whether the target is reachable. It is your number. The calculator makes it consequential, not correct.
- Attribution. Someone who finds you through search, leaves, and buys after a newsletter may be counted by analytics as a newsletter sale. Organic’s real contribution is often larger than the last click shows, and sometimes smaller.
- What happens after the period. Pages that rank keep bringing traffic after the spend stops, unlike an ad campaign. A 12-month model that has not paid back may pay back well in month 18. Try a longer horizon before concluding anything.
Pair it with the cost side
ROI is only as good as the cost figure under it. If the monthly cost is a guess, build it properly with the SEO cost calculator, which sums people, content, technical work, tools and outreach from your own inputs, then bring the total back here.
Frequently asked questions
How do you calculate SEO ROI?
ROI is the extra return from organic search minus what you spent, divided by what you spent. This calculator counts only sessions above today's level as the return, assumes they grow in a straight line to your target, and multiplies them by conversion rate, order value and margin.
Why only the extra sessions?
Because the traffic you already have would probably keep arriving without new spend. Crediting it to the budget makes almost any budget look profitable. If your traffic is falling and the spend is meant to stop the fall, that is a different model, and this one will understate it.
Why a straight-line ramp?
It is the simplest assumption that is not obviously wrong. Real SEO growth is lumpier, often slow for months and then faster once pages start ranking. A straight line is easy to reason about and easy to challenge, which is the point of showing it.
What is a good SEO ROI?
We are not going to quote one. Any benchmark figure mixes businesses with different margins, deal sizes and starting points, and the honest answer is whatever beats the other ways you could spend the same money. Compare this result with your paid acquisition cost for the same customers.
Does this include traffic from AI assistants?
Only if you put it in. Visits from AI answers show up in analytics as referrals from those assistants when they are tracked at all, so decide whether to count them as organic and be consistent.
More free tools
- Free Ad Copy Generator: Google, Meta, LinkedIn
- Free AI Article Generator: A Draft, Not an Article
- Free AI Crawler Simulator: See What GPTBot Sees
- Free Alt Text Generator for Images
- Free Article Rewriter: Change Tone, Keep Facts
- Free Article Summarizer: Claim, Evidence, Caveat
- Free Backlink Checker: Links and Referring Domains
- Free Blog Outline Generator: H2 and H3 Headings
- Free Blog Post Ideas From Real Searches
- Free Canonical Tag Checker: Test Any URL
- Free Character Counter With Title and Meta Limits
- Free Content Idea Generator
- Free CTA Generator: Call-to-Action Ideas
- Free Email Subject Line Generator
- Free FAQ Schema Generator (JSON-LD, Article, Breadcrumb)
- Free Google Rank Checker: Live Position for a Keyword
- Free Grammar Checker: Grammar, Spelling, Punctuation
- Free Headline Analyzer: Score Titles Before You Publish
- Free Headline Generator for Blog Posts
- Free Image Resizer and Compressor for the Web
- Free Internal Link Checker: Audit Anchors on Any Page
- Free JSON to CSV Converter, Nested Keys Flattened
- Free Keyword Clustering Tool: Group Keywords by Topic
- Free Keyword Combiner: Merge Word Lists Into Keywords
- Free Keyword Density Checker: A Diagnostic, Not a Target
- Free Keyword Research Tool: Volume, Difficulty, CPC
- Free Link Extractor: Every Link on a Page
- Free LSI Keyword Generator (Really: Related Terms)
- Free Meta Description Generator With SERP Preview
- Free Plagiarism Checker: Exact-Phrase Web Search
- Free robots.txt Generator With AI Crawler Rules
- Free robots.txt Tester: Is This URL Blocked?
- Free SEO Content Brief Template and Generator
- Free SEO Title Generator: Title Tags That Fit
- Free Slug Generator: Clean URL Slugs From Any Title
- Free Social Media Post Generator: X, LinkedIn, Instagram
- Free Website Metadata Checker: Title, OG, Schema
- Free Website Worth Calculator: Traffic Value Estimate
- Free Word Counter and Readability Checker
- Free XML Sitemap Checker and Validator
- Reading Level Checker: Flesch Score and Grade Level
- SEO Health Check: The Agency Audit Checklist
- SERP Analysis: How to Read a Search Result Page
- WordPress Permalink Generator: Preview Post URLs
Be the site the assistant names.
Add a domain and the first draft is written while you watch. Every publish is your decision, a click on the draft or a rule you set and can hold, and you can read the source or self-host it free.
Set up your site and read your first drafts before you enter a card.