# Magic Number Calculator MCP > 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. ## Overview - **Category:** finance - **Price:** Free - **Tags:** saas, gtm, efficiency, revenue, metrics ## Description 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. ## Tools ### 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. ## Prompt Examples **Prompt:** ``` Calculate my Magic Number with $500,000 Net New ARR and $400,000 S&M spend. ``` **Response:** ``` Your Magic Number is 1.25, which indicates an excellent level of efficiency. ``` **Prompt:** ``` What is the efficiency rating for a magic number of 0.4? ``` **Response:** ``` A Magic Number of 0.4 falls into the Inefficient tier, suggesting that your cost to acquire revenue is currently too high. ``` **Prompt:** ``` Evaluate my GTM health: $200,000 Net New ARR and $300,000 S&M spend. ``` **Response:** ``` Your GTM health status is Inefficient. The current ratio of 0.67 suggests your growth engine needs optimization to improve capital efficiency. ``` ## Capabilities ### Calculate the raw growth ratio Get the exact number representing your revenue growth relative to marketing spend. ### Categorize your performance tier See if your current growth metrics fall into Inefficient, Healthy, or Excellent categories. ### Get a full growth diagnostic Receive a complete summary of your growth engine's health and scaling efficiency. ### Compare revenue to spend Instantly see how much new revenue you're generating against your previous spending. ### Identify budget waste Spot when your cost to acquire revenue is climbing too high for your current scale. ### Determine growth health status Get a clear status update on whether your growth engine is performing as expected. ## Use Cases ### 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. ## Benefits - 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. ## How It Works The bottom line is you get a clear, data-backed answer on whether your growth spend is actually working. 1. Give your agent your Net New ARR and previous S&M spend. 2. The MCP calculates the efficiency ratio and performance tier. 3. You get a clear health summary and a raw growth number. ## Frequently Asked Questions **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.