Magic Number Calculator MCP for AI. Stop guessing if your marketing spend is working.
Works with every AI agent you already use
…and any MCP-compatible client








Connect to your AI in seconds.
Magic Number Calculator helps you figure out if your sales and marketing spend is actually working. It takes your Net New ARR and compares it against your S&M spend to give you a clear picture of your growth engine's health.
Stop guessing if your spend is efficient and start using a concrete ratio to guide your budget. Use it to spot waste, justify spend, and see your scaling efficiency clearly.
What your AI can do
Calculate magic number
Calculates the raw ratio of Net New ARR to S&M spend.
Evaluate gtm health summary
Generates a full diagnostic report on your growth engine's efficiency.
Get efficiency rating
Assigns your Magic Number to a specific performance tier like Inefficient or Excellent.
Get the exact number representing your revenue growth relative to marketing spend.
See if your current growth metrics fall into Inefficient, Healthy, or Excellent categories.
Receive a complete summary of your growth engine's health and scaling efficiency.
Instantly see how much new revenue you're generating against your previous spending.
Spot when your cost to acquire revenue is climbing too high for your current scale.
Get a clear status update on whether your growth engine is performing as expected.
Ask an AI about this
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Magic Number Calculator (3 tools)
Get instant growth efficiency ratios and GTM health diagnostics with three specialized tools.
Make your AI actually useful.
Add this MCP to Claude, Cursor, or Windsurf and your AI stops guessing. It gets real tools to look things up, take action, and handle the stuff you keep doing by hand.
Start using Magic Number Calculator on VinkiusCalculate Magic Number
Calculates the raw ratio of Net New ARR to S&M spend.
Evaluate Gtm Health Summary
Generates a full diagnostic report on your growth engine's efficiency.
Get Efficiency Rating
Assigns your Magic Number to a specific performance tier like Inefficient or...
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Works with Claude, ChatGPT, Cursor, and more
The Model Context Protocol standardizes how applications expose capabilities to LLMs. Instead of operating in isolation, your AI gains direct access to external platforms, live data, and real-world actions through secure, standardized connections.
This connection provides 3 powerful capabilities that interface natively with Claude, ChatGPT, Cursor, and other compatible AI platforms. No middleware. No custom integration required.
Stop guessing if your marketing spend is actually working.
Most growth teams end up with a mess of spreadsheets. You're constantly pulling Net New ARR from one tab and S&M spend from another, trying to remember which quarter's data belongs where. You do the math, double-check it, and then try to explain the result to a CFO who just wants to know if the money is being wasted.
This MCP cuts that out. You just tell your agent the numbers, and it gives you the ratio and a health rating instantly. You move from manual data entry to having a clear diagnostic of your growth engine's efficiency in seconds.
Magic Number Calculator gives you a clear growth diagnostic.
No more manual math, no more hunting for spend figures in different accounts, and no more vibes-based reporting.
You get a straight answer on your growth efficiency every single time.
What your AI can actually do with this
Most growth teams struggle to tell if they're actually being efficient or just throwing money at a problem. You need a way to see if your spend is yielding a return that makes sense for your current scale. This MCP does the heavy lifting by crunching those specific numbers for you.
Instead of jumping between spreadsheets and manually calculating ratios every time a stakeholder asks for an update, you just ask your agent to run the numbers. It looks at your current revenue against your previous spending to tell you exactly where you stand. Because it's part of the Vinkius catalog, you can plug it right into your existing setup and get answers in seconds.
It's about moving from "I think we're doing well" to "here is the exact ratio of our efficiency." You get a clear diagnostic of your business scaling without the manual math errors that plague big spreadsheets. It helps you spot when your cost to acquire revenue is getting too high before it becomes a major problem.
You can get a performance tier that tells you if you're in the "Excellent" range or if you need to pull back on the marketing spend. It turns a messy data pull into a single, actionable number that you can actually use in a meeting.
019ee3e4-e374-734a-9b41-5864d86024ba Here's how it actually works
The bottom line is you get a clear, data-backed answer on whether your growth spend is actually working.
Give your agent your Net New ARR and previous S&M spend.
The MCP calculates the efficiency ratio and performance tier.
You get a clear health summary and a raw growth number.
Who is this actually for?
This is for the RevOps lead who's tired of defending the marketing budget to a skeptical CFO. They need a way to prove that the money spent is actually yielding a return, moving the conversation from vague vibes to hard, quantifiable efficiency ratios that justify every dollar of the GTM budget.
Auditing the cost of customer acquisition to see if the current strategy is sustainable.
Needs to justify next quarter's spend by showing how efficiently the current budget is converting to ARR.
Looking for a high-level health check on how much capital is being burned to generate new revenue.
What Changes When You Connect
Stop manually calculating ratios in spreadsheets by using calculate_magic_number to get instant results. This removes the risk of human error and lets you get a clear picture of your spend efficiency in one step.
Get a clear "Excellent" or "Inefficient" label for your growth strategy using get_efficiency_rating to remove the guesswork. This helps you communicate your performance to stakeholders without having to explain the underlying math every time.
Receive a complete diagnostic of your scaling health with evaluate_gtm_health_summary instead of just a raw number. It gives you the context you need to tell a story about how the business is actually growing.
Spot budget waste faster by identifying when your spend is too high relative to your new revenue. By using calculate_magic_number regularly, you can catch overspending early and pivot your strategy before it hits the bottom line.
Provide instant answers to leadership questions about growth efficiency without digging through old reports. Having these metrics ready via your agent means you're always prepared for the how and why of your marketing spend.
See it in action
Justifying marketing spend
A RevOps lead wants to see if a $400k spend on a $500k ARR gain is actually good. They ask the agent to calculate the magic number.
Preparing for a board meeting
A Marketing Director needs to know if their current growth is Healthy or Inefficient before the board meeting. They use get_efficiency_rating.
Checking scaling sustainability
A founder wants to know if their scaling is sustainable. They ask the agent to evaluate the GTM health summary for their last two quarters.
Audit of new channels
A finance analyst is checking if a new marketing channel is worth the spend. They run calculate_magic_number to see the efficiency ratio.
The honest tradeoffs
Guessing growth based on vibes
I feel like our spend is too high.
Use calculate_magic_number to get the hard ratio.
Manual spreadsheet math errors
Trying to calculate ratios by hand in a messy Excel sheet.
Use calculate_magic_number to get the exact ratio every time.
Ignoring the cost of revenue
Our revenue is up, so we're winning.
Use evaluate_gtm_health_summary to see if that revenue cost too much to get.
Vague performance reporting
We're doing pretty well with our spend.
Use get_efficiency_rating to show your actual performance tier.
When It Fits, When It Doesn't
Use this if you need to quantify the efficiency of your sales and marketing spend relative to new revenue. It's perfect for RevOps teams, marketing leads, and finance folks who need a "Magic Number" to justify budgets or identify waste. Don't use this if you just want to track raw revenue totals or lead counts; you'd need a standard CRM connector for that. This is specifically for the ratio of spend to growth. If you need deep-dive attribution on every dollar spent, this tool is too high-level, and you'd want a dedicated marketing analytics platform instead.
Questions you might have
What does the Magic Number Calculator actually do? +
It calculates the ratio of your Net New ARR to your previous S&M spend to show how efficiently you're growing.
How do I know if my growth is healthy with the Magic Number Calculator? +
You can use get_efficiency_rating to see if your ratio falls into the Inefficient, Healthy, or Excellent tiers.
Can the Magic Number Calculator give me a full report? +
Yes, use evaluate_gtm_health_summary to get a complete diagnostic of your growth engine's efficiency.
What numbers do I need for the Magic Number Calculator? +
You need your Net New ARR from the current quarter and your S&M spend from the previous quarter.
Is the Magic Number Calculator good for SaaS companies? +
It's a standard metric for SaaS and any business that spends on sales and marketing to acquire revenue.
Which AI clients are compatible with the Magic Number Calculator? +
You can use this MCP with any AI client that supports the Model Context Protocol. This includes Claude, Cursor, Windsurf, and VS Code.
Does the Magic Number Calculator store my sensitive financial data? +
No, your data is not stored. The MCP processes the numbers you provide during your chat session to give you instant results without keeping your records.
How do I set up the Magic Number Calculator in my AI client? +
You connect it through the Vinkius platform. Once you're subscribed, your AI client will automatically see the tools so you can start running calculations.
We've already built the connector for Magic Number Calculator. Just plug in your AI agents and start using Vinkius.
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