Calculate Body Mass Index and the corresponding WHO weight category for an adult. Inputs: weight_kg (kilograms) and height_cm (centimeters). Returns the BMI value and category. Read-only and deterministic. Screening indicator only — not a medical diagnosis; not valid for children or athletes with high muscle mass.

Calculate Canadian FEDERAL income tax using CRA brackets and the basic personal amount. Use for a federal-only estimate; provincial/territorial tax and CPP/EI are NOT included, so the real total tax is higher. Input: income_cad (annual income in CAD). Returns basic personal amount, taxable income, federal tax, effective and marginal rates. Read-only, deterministic, estimate only.

Compute compound growth of a lump sum with A = P·(1+r/n)^(n·t). Use for savings, investment or retirement projections without periodic contributions. Inputs: principal (initial amount), annual_rate (annual rate in percent), years (duration), optional compounds_per_year (compounding frequency, default annual). Returns final amount, total interest earned and a yearly breakdown. Read-only, deterministic. For loans/repayments use calculate_loan_payment or calculate_mortgage instead.

Calculate French personal income tax (impôt sur le revenu) for the 2026 tax year using the official progressive brackets (Article 197 CGI) and the family-quotient system. Use when the user asks how much income tax they owe in France. Inputs: income (annual net taxable income in EUR) and optional parts (number of family-quotient shares, default 1 — e.g. 2 for a married couple, 2.5 with one child). Returns total tax, effective and marginal rates, and the per-bracket breakdown. Read-only and deterministic: same inputs always give the same result; no data is stored. Not tax advice. For payroll gross-to-net conversion use calculate_french_salary instead.

Convert a French gross salary to net salary for 2026, applying the social-contribution rates of the selected employment status. Use when the user knows their gross pay and wants their take-home pay in France. Inputs: gross_monthly (gross monthly salary in EUR) and optional status ('cadre', 'non-cadre' or civil servant — see the enum). Returns monthly and annual net, total social contributions, and employer cost. Read-only, deterministic estimate based on standard rates; individual company agreements may differ. For income tax on that salary, use calculate_french_income_tax.

Calculate the fixed monthly payment of a generic amortizing loan when the term is expressed in months. Inputs: principal (amount borrowed), annual_rate (annual interest rate in percent), months (term in months). Returns monthly payment, total cost and total interest. Read-only and deterministic. Prefer calculate_mortgage if you want a term in years or an amortization schedule.

Calculate the fixed monthly payment, total interest and total cost of a mortgage or amortizing loan, with an optional month-by-month amortization schedule. Use for home-loan or any fixed-rate amortizing loan questions in any currency. Inputs: principal (amount borrowed), annual_rate (nominal annual interest rate in percent, e.g. 3.5), years (term in years), optional with_schedule (boolean — include the full amortization table). Read-only and deterministic. Does not include insurance, taxes or fees.

Perform one of three percentage operations selected by operation: the value of a percent of a total, the percentage change between two values, or what percent one value is of another. Inputs: operation (see enum), a and b (the two operands — their meaning depends on the operation, as described in the parameter docs). Returns the numeric result with the applied formula. Read-only and deterministic.

Calculate Total Daily Energy Expenditure (maintenance calories) by multiplying a Basal Metabolic Rate by a standard activity factor. Inputs: bmr (basal metabolic rate in kcal — compute it first if unknown) and activity_level (see enum, from sedentary to very active). Returns TDEE in kcal/day. Read-only and deterministic. General guidance, not medical or dietary advice.

Calculate UK income tax for the 2025/26 tax year using HMRC bands, including the personal-allowance taper above £100,000. Use for England/Wales/NI income tax questions (National Insurance is not included; Scottish bands are not modelled). Input: income (annual gross income in GBP). Returns personal allowance, taxable income, income tax, effective and marginal rates. Read-only, deterministic, estimate only.

Calculate US federal income tax for tax year 2026 using the IRS progressive brackets and the standard deduction for the chosen filing status. Use for a quick federal-only estimate; it does NOT include state income tax or FICA payroll taxes. Inputs: income (annual gross income in USD) and optional filing_status. Returns taxable income after standard deduction, federal tax, effective and marginal rates. Read-only and deterministic. Estimates only — not tax advice.

Add or remove VAT/GST/sales tax at any custom rate, for any country. Inputs: amount, rate (tax rate in percent) and optional mode (whether amount is before-tax or after-tax — see enum). Returns amount before tax, amount after tax and the tax amount. Read-only and deterministic. Country-specific helpers (French/UK/Swiss VAT…) exist in the full catalog via get_bundle_tools('finance-universal').

Invoke ANY of the 446 calculators of the hosted macalc catalog by name — not just the core tools listed by this server. Workflow: 1) list_bundles to find the right domain, 2) get_bundle_tools(bundle_id) to get the exact tool name and its parameters, 3) call_any_calculator with that tool_name and its arguments object. The call is forwarded verbatim to the hosted macalc API (network request, no authentication, nothing stored beyond anonymous usage counters). Read-only and deterministic for a given catalog version. Returns the target calculator's JSON result ({result, formula, source, reference_url}) or a clear error if the tool name is unknown.

Return the tool names and descriptions inside one thematic bundle of the full macalc catalog. Use after list_bundles to discover a specific calculator, then invoke it with call_any_calculator. Input: bundle_id (one of the enum values, e.g. 'finance-france', 'sante', 'math'). Read-only and deterministic.

List the 31 thematic bundles that organize the full macalc catalog of 446 calculators (finance by country, real-estate, health, math, construction, conversions…). Use this FIRST when the user needs a calculator that is not among this server's core tools, then call get_bundle_tools to see the tools of the relevant bundle. Takes no meaningful parameters. Read-only, deterministic, returns the same catalog every time.