Percentage Calculator MCP Server

Percentage Calculator

Use this provider for standard percentage arithmetic without hand-rolling formulas.

Capabilities

• X% of Y: What is a given percent of a base amount (e.g. what is 15% of 200).
• X is what % of Y: Express the first number as a percentage of the second (the whole).
• Percent change: How much the value moved from a starting amount to an ending amount, as a percentage of the absolute starting amount.
• Add a percent: Increase a value by a given percentage (compound-style scaling on that single step).
• Subtract a percent: Decrease a value by a given percentage (same scaling pattern).

Gotchas

• Percent change from zero: If the starting value (baseline) is zero, percent change is undefined and the tool returns an error.
• Division by zero: "What percent" requires a non-zero whole (second_value).
• Negative numbers: All operands may be negative; interpret results in context (e.g. percent change still uses the absolute baseline in the denominator).
• Rounding: Numeric result is rounded to four decimal places.