Percentage Calculation Engine MCP for AI. Never let the AI guess your financial math again.

Q: Does it support tax addition?

Yes, simply use the increaseby function.

Q: When should I use calculateincreaseby versus calculatepercentof with the Percentage Calculation Engine?

Use calculatepercentof when you need to find a percentage of a base number (e.g., 15% of $200). Use calculateincreaseby when the change is relative, like applying an adjustment or discount rate directly to an amount.

Claude

ChatGPT

Cursor

Gemini

Windsurf

VS Code

JetBrains

Vercel

See Vinkius in Action

Works with every AI agent you already use

…and any MCP-compatible client

Connect to your AI in seconds.

Percentage Calculation Engine calculates exact percentages, discounts, and relative increases every time. Stop relying on LLMs for financial math; this server runs pure JavaScript logic at the edge.

It lets your AI client perform deterministic calculations for VAT rates, invoice discounts, and interest accrual, giving you a reliable source of truth for complex quantitative reporting.

What your AI can do

Calculate increase by

Changes a starting value up or down by a specified percentage. Use a negative percent for discounts.

Calculate percent of

Computes exactly what X percent of a given base total is. Great for tax calculations and finding discount values.

Calculate Sales Tax and VAT

Pass a base price and tax rate to determine the final amount including Value Added Tax (VAT) or sales tax.

Apply Discounts and Coupons

Determine the reduced total by applying a percentage discount to an original cost, simulating coupon use.

Compute Relative Increases

Adjust a starting value up or down by a specified percentage, useful for calculating growth rates or depreciation.

Determine Percentage of Total

Calculate what specific portion (X%) represents out of a larger base total. Essential for financial reporting summaries.

Handle Layered Math

Run multiple calculations sequentially—for example, taking a discount off an item price and then applying tax to the discounted subtotal.

Ask an AI about this

Included with Plan

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AI Agent

Percentage Calculation Engine MCP Server: 2 Tools for Finance

Use these two tools to compute accurate percentages for anything from e-commerce discounts to payroll tax rates. No approximation involved.

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 Percentage Calculation Engine on Vinkius

Calculate Increase By

Changes a starting value up or down by a specified percentage. Use a negative percent for discounts.

Calculate Percent Of

Computes exactly what X percent of a given base total is. Great for tax calculations...

Security and governance baked right in.

Pick your AI client below to get set up. Just create a Vinkius account, subscribe, and you're instantly up and running. We handle the entire backend infrastructure, delivering out-of-the-box support for HTTPS Streamable, SSE, and OAuth2—zero messy routing required.

Claude AI

Open Claude Settings

Go to claude.ai, click your profile icon, then navigate to Customize → Connectors.

Add Custom Connector

Click the "+" button and select Add custom connector. Paste your Vinkius endpoint URL:

https://edge.vinkius.com/[YOUR_TOKEN_HERE]/mcp

Replace [YOUR_TOKEN_HERE] with your token from cloud.vinkius.com. For OAuth-protected servers, expand Advanced settings to add credentials.

Start a conversation

Open a new chat. The Percentage Calculation Engine integration is available immediately — no restart needed.

Antigravity

Configure Agent Environment

Open your Antigravity agent's workspace configuration or mcp-servers.json file.

Bind the Endpoint

Add the Vinkius endpoint URL to your agent's MCP connections list:

"mcp_servers": {
  "percentage-calculation-engine": {
    "serverUrl": "https://edge.vinkius.com/[YOUR_TOKEN_HERE]/mcp"
  }
}

Provide your secure token in place of [YOUR_TOKEN_HERE] to ensure your agent requests are authenticated.

Execute

Start your Antigravity session. The agent will autonomously discover and utilize the Percentage Calculation Engine tools with full Vinkius guardrails applied.

VS Code Copilot

⚡

One-Click Install (Recommended)

In your Vinkius Dashboard, simply click the Add to VS Code button for this server. We'll automatically configure your local workspace.

Or configure manually

Open MCP Settings

Open VS Code, press Ctrl/Cmd + Shift + P, and search for GitHub Copilot: MCP Servers.

Add Server Config

Add the Vinkius endpoint configuration to your mcp-servers.json file:

"percentage-calculation-engine": {
  "url": "https://edge.vinkius.com/[YOUR_TOKEN_HERE]/mcp"
}

Ensure you replace [YOUR_TOKEN_HERE] with your token from cloud.vinkius.com.

LangChain

Install Dependencies

Install the LangChain MCP adapters for your environment:

pip install langchain-mcp-adapters

Connect the Server

Use the SSEClient in LangChain to connect to the Vinkius managed endpoint:

from langchain_mcp_adapters.client import SSEClient

# Connect to Vinkius
client = SSEClient(url="https://edge.vinkius.com/[YOUR_TOKEN_HERE]/mcp")
tools = client.get_tools()

CrewAI

Define the Tool

Load the Vinkius MCP tools into your CrewAI agents:

from crewai import Agent
from mcp_crewai import MCPTool

# Connect securely to Vinkius
vinkius_tools = MCPTool(url="https://edge.vinkius.com/[YOUR_TOKEN_HERE]/mcp")

# Assign to Agent
researcher = Agent(
    role='Data Researcher',
    tools=vinkius_tools.get_all()
)

Execute Task

Run your CrewAI process. The agent will autonomously route tasks to the Vinkius managed server.

Choose How to Get Started

Build a custom MCP for your own tools, or connect a ready-made integration from our catalog.

Build Your Own

Turn any API into an MCP. Import a spec, define Agent Skills, or deploy with MCPFusion.

Import from OpenAPI, Swagger, or YAML specs
Create Agent Skills with progressive disclosure
Deploy to edge with MCPFusion framework
Built in DLP, auth, and compliance on every call
Real time usage dashboard and cost metering
Publish to catalog or keep private

Start building

Make Your AI Do More

Start with Percentage Calculation Engine, then connect any of our 5,100+ other servers whenever your AI needs more. One click, no limits.

Use this MCP plus 5,100+ others, all in one place
Add new capabilities to your AI anytime you want
Every connection is secured and compliant automatically
Track usage and costs across all your servers
Works with Claude, ChatGPT, Cursor, and more
New servers added to the catalog every week

Percentage Calculation Engine MCP server cover

Independent Platform Disclaimer: Vinkius is an independent platform and is not affiliated with, endorsed by, sponsored by, verified by, or otherwise authorized by JavaScript Math. All third-party trademarks, logos, and brand names are the property of their respective owners. Their use on this website is strictly for informational purposes to identify service compatibility and interoperability.

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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 2 powerful capabilities that interface natively with Claude, ChatGPT, Cursor, and other compatible AI platforms. No middleware. No custom integration required.

Calculating tax or discounts shouldn't feel like a guessing game.

Right now, if you need to calculate VAT on an item after applying a coupon, you're either copy-pasting complex formulas into a spreadsheet, running calculations through an LLM that might round the numbers incorrectly, or manually checking every single line item. It’s slow and it introduces risk.

With this MCP server, your agent handles it instantly. You simply tell it to run the calculation—for instance, 'What is 20% of $500?'—and you get a definitive answer back. The uncertainty vanishes.

Percentage Calculation Engine: Get precise financials in two steps.

Forget opening three different tabs to find the correct formula for discount, tax, and net price. You don't have to remember if you should subtract or add percentages. The engine manages the pure math logic behind the scenes.

Now, your agent handles complex financial adjustments instantly. It runs flawless mathematical evaluations every time—no more guessing.

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What your AI can actually do with this

Listen up: when you're dealing with money, you can't trust a language model to do the math. LLMs are great for talking, but they guess at numbers; they don't calculate them. This Percentage Calculation Engine is your fix. It runs pure JavaScript logic directly through your AI client, making sure every number it spits out is deterministic—meaning the answer will be exactly the same time after time, no matter how you prompt it.

The engine gives your agent two specific tools: calculate_increase_by and calculate_percent_of. You just feed it raw numbers—the base amount and the percentage. The server runs the math using pure JavaScript, giving back an absolute number every single time. No approximations allowed here. Just accurate financials.

This tool set lets you calculate sales tax and VAT rates by passing a base price and the required tax rate to determine the final total including Value Added Tax (VAT) or standard sales tax. You can use calculate_percent_of to figure out exactly what specific portion—say, 7%—represents out of a larger base total; this is essential when you're summarizing financial reports for clients.

When it comes time to apply discounts and coupons, the server uses calculate_increase_by. You pass the original cost, and then use a negative percentage. This immediately tells you the reduced total by applying the discount, simulating how a coupon works at the checkout counter. It’s perfect for figuring out markdown values or tiered pricing structures.

If you need to compute relative increases—like calculating annual growth rates, depreciation, or investment gains—you call calculate_increase_by. You adjust a starting value up or down by a specified percentage. This gives you the precise new value, whether it's positive growth or negative decline.

What makes this powerful is that you can handle layered math. For instance, imagine an item has a coupon applied to it first; then the tax gets added to that discounted subtotal. You run multiple calculations sequentially: use calculate_increase_by to get the pre-tax discount price, and then feed that result into another calculation (or back into calculate_percent_of) to apply the final sales tax rate.

This gives you a reliable source of truth for complex quantitative reporting.

You need certainty when dealing with invoices, payroll processing, or e-commerce checkouts. Instead of risking an AI hallucination on basic arithmetic, this engine provides your agent with a calculator that never guesses. It’s pure, raw math logic built into the toolset.

Built · Hosted · Managed by Vinkius Percentage Calculation Engine - Calculate Taxes & Discounts

Server ID 019e38d5-9f3e-70b6-be47-44c71c004477

Vinkius Inspector

Compliance Grade F

Score 43.65/100

Report View Report ↗

Here's how it actually works

The bottom line is that you send raw numbers to the engine and get a mathematically proven final value back. No guessing involved.

Start by providing your AI client with two numbers: the base value (e.g., $500) and the percentage change (e.g., 20%).

The agent invokes a tool, like calculate_percent_of, which runs the math using deterministic JavaScript logic.

You get back one precise number representing the calculated result—the exact tax amount, discount, or new total.

What Changes When You Connect

Stop rounding errors. The engine guarantees precise, fractional calculations for VAT and taxes, removing guesswork from your final invoice total.

Process layered discounts accurately. You can chain calls to calculate a discount off a price before applying tax, maintaining mathematical rigor.

Ensure consistent growth metrics. Use calculate_increase_by to reliably determine year-over-year percentage changes for reporting without variance.

Build accurate checkout logic. Determine the exact coupon value or proportional fee using calculate_percent_of, making your e-commerce platform reliable.

Handle negative adjustments easily. Applying a discount is just another calculation; use a negative percent input in calculate_increase_by to find the new, lower total.

See it in action

01 01

Processing an E-commerce Checkout

A customer's cart totals $1000. The agent needs to apply a 10% coupon discount and then calculate the 20% VAT on the reduced total. The agent calls calculate_percent_of twice in sequence, ensuring the tax is applied only to the discounted amount, resulting in a perfect final checkout price.

02 02

Calculating Quarterly Sales Commission

A salesperson made $50,000 in revenue. Their commission is 12%. The agent uses calculate_percent_of to immediately determine the exact commission amount ($6,000) and can then calculate their yearly projected earnings by applying a growth rate increase.

03 03

Writing Off Inventory Value

A warehouse needs to write down old stock valued at $15,000 due to obsolescence. The agent uses calculate_increase_by with a negative percentage (e.g., -25%) to determine the precise new book value of the inventory.

04 04

Determining Payroll Tax Liabilities

The payroll system calculates gross wages ($8,000) and needs to know the exact withholding tax at 6.5%. The agent calls calculate_percent_of with this data, getting a precise number that must match legal requirements.

The honest tradeoffs

Asking the AI for complex math in one prompt

Anti-pattern

Prompting: 'Calculate 15% off $200 and then add 7% tax to that result.' The AI often gets it wrong or uses approximations.

The Fix

Break it down. First, use calculate_increase_by with a -15% value on the base price. Then, take that new total and use calculate_percent_of to add the 7% tax. This two-step process guarantees accuracy.

Using generic calculators for finance

Anti-pattern

Relying on built-in LLM functions or basic code blocks that might round numbers or handle currency units inconsistently.

The Fix

Use the dedicated tools. The calculate_percent_of tool is specifically designed to compute percentages relative to a base, ensuring financial standards are met.

Trying to do statistical averages

Anti-pattern

Attempting to calculate weighted averages or standard deviations with only basic percentage tools.

The Fix

This engine handles simple proportional changes. If you need advanced statistics, look for a dedicated statistical modeling tool instead.

When It Fits, When It Doesn't

Use this Percentage Calculation Engine if your math is based on clear proportions: tax rates, discounts, interest accruals, or fixed percentage increases/decreases. It's mandatory when accuracy trumps everything else.

Don't use it if you need to calculate anything involving qualitative data, fuzzy logic, or non-linear trends (like predicting market sentiment). For those cases, a general reasoning engine is better. Also, if your calculation involves complex statistical modeling (e.g., calculating correlation coefficients), this utility server isn't enough—you'll need specialized math libraries. However, for 90% of standard financial reporting and e-commerce logic, the deterministic nature of calculate_increase_by and calculate_percent_of makes this the right call.

Questions you might have

Can it calculate discounts? +

Yes, by passing a negative percentage.

Is it deterministic? +

Absolutely. Pure math evaluation local.

Does it support tax addition? +

Yes, simply use the increase_by function.

When should I use `calculate_increase_by` versus `calculate_percent_of` with the Percentage Calculation Engine? +

Use calculate_percent_of when you need to find a percentage of a base number (e.g., 15% of $200). Use calculate_increase_by when the change is relative, like applying an adjustment or discount rate directly to an amount.

How does the Percentage Calculation Engine handle invalid or missing financial inputs? +

The server validates all inputs using native JavaScript math logic. If a required value is missing or improperly formatted, the tool returns a specific error code instead of attempting to guess an answer. This keeps your data flow clean.

Does running `calculate_percent_of` impact performance for complex financial reports? +

No. Because the math runs as pure JavaScript at the edge, it operates outside the LLM's main processing layer. This design keeps latency low, even when you run multiple successive percentage checks.

Can the Percentage Calculation Engine accurately handle floating-point precision for currency? +

Yes, it handles financial precision correctly because it utilizes native JavaScript math standards. You get accurate results for currency calculations without the rounding errors that can plague general LLM processing.

Is the Percentage Calculation Engine limited to US dollar or Euro calculations? +

The engine is designed around pure mathematical logic, not specific currencies. It works with any numerical input you provide (e.g., USD, EUR) as long as the values are structured correctly.

Connect to your AI in seconds.

Calculate increase by

Calculate percent of

Percentage Calculation Engine MCP Server: 2 Tools for Finance

Make your AI actually useful.

Calculate Increase By

Calculate Percent Of

Security and governance baked right in.

Claude AI

Open Claude Settings

Add Custom Connector

Start a conversation

Claude Code

Open your terminal

Add the MCP Server

Start coding

Cursor

One-Click Install (Recommended)

Open Cursor Settings

Add New Server

Use in Composer

Antigravity

Configure Agent Environment

Bind the Endpoint

Execute

VS Code Copilot

One-Click Install (Recommended)

Open MCP Settings

Add Server Config

Windsurf

One-Click Install (Recommended)

Open Windsurf Settings

Add Server Endpoint

LangChain

Install Dependencies

Connect the Server

CrewAI

Define the Tool

Execute Task

Choose How to Get Started

Build Your Own

Make Your AI Do More

Works with Claude, ChatGPT, Cursor, and more

Calculating tax or discounts shouldn't feel like a guessing game.

Percentage Calculation Engine: Get precise financials in two steps.

What your AI can actually do with this

Here's how it actually works

Who is this actually for?

What Changes When You Connect

See it in action

Processing an E-commerce Checkout

Calculating Quarterly Sales Commission

Writing Off Inventory Value

Determining Payroll Tax Liabilities

The honest tradeoffs

Asking the AI for complex math in one prompt

Using generic calculators for finance

Trying to do statistical averages

When It Fits, When It Doesn't

Questions you might have