# Xearno Tools

> A bench of deterministic, tested calculators for money and business decisions,
> built for humans and AI agents alike. Every tool computes values AND returns
> benchmark-based insights (the read an experienced operator would give).
> Call a tool instead of doing financial arithmetic in-context.

## How to call tools

- REST: POST https://xearno.tools/api/v1/tools/{slug} with JSON matching the tool's inputSchema.
  GET the same URL for the schema; GET https://xearno.tools/api/v1/tools for the full list.
- MCP: https://xearno.tools/mcp (streamable HTTP, stateless). Tool names are the slugs with underscores.
- No authentication required. Responses are deterministic JSON:
  { "results": [...display values], "insights": [{level, text}...], "raw": {stable numeric keys} }

## Xearno Fortune Tools

- [Compound Growth](https://xearno.tools/t/compound-growth): What a starting amount plus monthly contributions grows into over time. Projects the future value of a lump sum plus recurring monthly contributions at a given annual return, compounded monthly. Splits the outcome into what you put in versus what compounding earned, and sanity-checks the assumptions. (tags: growing, planning)
- [Savings Goal](https://xearno.tools/t/savings-goal): The monthly saving needed to hit a target by a deadline. Given a target amount, what you already have, a time horizon, and an expected return, computes the required monthly contribution — and shows what waiting a year would cost you. (tags: saving, planning)
- [Loan Payment](https://xearno.tools/t/loan-payment): Monthly payment, total interest, and what paying extra saves. Standard amortized loan math: monthly payment, total cost, interest as a share of principal — plus a concrete extra-payment scenario showing time and interest saved. (tags: protecting, planning, spending)
- [FIRE Number](https://xearno.tools/t/fire-number): The portfolio that makes work optional, and how far away it is. Computes your financial-independence target from annual spending and a safe withdrawal rate, then projects how many years your current savings and monthly contributions take to reach it. (tags: planning, growing, earning)
- [Split Bill](https://xearno.tools/t/split-bill): Even split with tip, rounded so nobody argues. Splits a bill evenly across people with an optional tip, and shows the clean rounded amount plus who covers the remainder. (tags: spending)
- [Unit Price](https://xearno.tools/t/unit-price): Which package is actually cheaper per unit. Compares two package options by price per unit and quantifies the savings — the supermarket-shelf math, done honestly. (tags: saving, spending)
- [Percentage Calculator](https://xearno.tools/t/percentage): What is X% of Y, X is what percent of Y, and percent change — all three, correctly. The three percentage questions people actually ask: a percent of a number, what percent one number is of another, and the percent change between two numbers — with the classic traps (reversal, asymmetric change) called out. (tags: everyday)
- [Discount Calculator](https://xearno.tools/t/discount): Sale price after one or two stacked discounts — and why 20% + 10% is not 30% off. Final price and amount saved after a discount, with optional second stacked discount (coupon on top of sale). Shows the true combined percentage, which is always less than the sum. (tags: spending, saving, everyday)
- [Tip Calculator](https://xearno.tools/t/tip): Tip, total, and per-person share — with actual tipping norms by region. Computes the tip, the grand total, and each person’s share, and — the part most tip calculators skip — tells you what a normal tip actually is in the US, Europe, and Asia. (tags: spending, everyday)
- [Salary ↔ Hourly Converter](https://xearno.tools/t/salary-to-hourly): Convert between hourly, weekly, monthly, and annual pay at your real hours. One rate in, the whole grid out: hourly, daily, weekly, monthly, and annual pay, at your actual hours per week and working weeks per year — not the idealized 2,080-hour year unless that’s what you work. (tags: earning, everyday)
- [Overtime Pay Calculator](https://xearno.tools/t/overtime-pay): Time-and-a-half math: weekly gross with overtime, and your blended hourly rate. Weekly gross pay from regular hours plus overtime at any multiplier (1.5×, 2×), including the blended effective hourly rate the overtime produces. (tags: earning, everyday)
- [Pay Raise Calculator](https://xearno.tools/t/pay-raise): What a raise is worth — and whether it beats inflation at all. Converts a raise percentage into new salary and monthly difference, then answers the question that matters: after inflation, is it actually a raise? (tags: earning, everyday)
- [Simple Interest Calculator](https://xearno.tools/t/simple-interest): I = P·r·t — and how far it diverges from compound interest over time. Simple interest on a principal over time, with the side-by-side compound comparison that shows why the distinction matters more each year. (tags: growing, everyday)
- [APR ↔ APY Converter](https://xearno.tools/t/apr-to-apy): Nominal vs effective rates — what a quoted APR really costs at your compounding frequency. Converts between nominal APR and effective APY at any compounding frequency. This is the difference between what a rate is called and what it actually does to your balance. (tags: growing, protecting, everyday)
- [Mortgage Calculator](https://xearno.tools/t/mortgage): True monthly cost — principal & interest plus taxes, insurance, and PMI, not just the loan. Monthly mortgage payment from price, down payment, rate, and term — including the parts lender ads leave out: property tax, home insurance, and PMI when the down payment is under 20%. The headline number here is the full PITI cost of owning. (tags: spending, protecting, planning)
- [Car Loan Calculator](https://xearno.tools/t/car-loan): Monthly car payment with down payment, trade-in, and sales tax — and the long-loan trap. Auto loan payment from vehicle price, down payment, trade-in, sales tax, rate, and term — with the negative-equity warning the dealership finance office will not give you. (tags: spending, planning)
- [EMI Calculator](https://xearno.tools/t/emi): Loan EMI, total interest, and the flat-rate trap that makes 10% cost like 18%. Equated Monthly Instalment for any loan — home, car, personal — with total interest over the tenure and the one warning every borrower comparing offers needs: flat rate and reducing-balance rate are not the same thing. (tags: spending, planning)
- [SIP Calculator](https://xearno.tools/t/sip): Systematic Investment Plan returns — with optional annual step-up, honestly assumed. Projects a monthly SIP (systematic investment plan) to its future corpus, splits invested amount from gains, and supports the annual step-up that matches how salaries actually grow. (tags: growing, planning)
- [Credit Card Payoff Calculator](https://xearno.tools/t/credit-card-payoff): How long your balance really takes to clear — and the minimum-payment trap in numbers. Months and total interest to pay off a credit card balance at your APR and monthly payment, with the concrete payoff acceleration from paying more — the math credit card statements are legally required to hint at and everyone ignores. (tags: protecting, spending)
- [Home Affordability Calculator](https://xearno.tools/t/home-affordability): How much house you can afford by the 28/36 rule — the underwriting math, honestly applied. Maximum affordable home price from income, existing debts, down payment, and rate — using the 28/36 debt-to-income rule lenders actually underwrite with, and flagging when the two limits disagree. (tags: planning, spending)
- [Currency Converter](https://xearno.tools/t/currency): Convert between 31 currencies at the official ECB reference rate — and know what your bank adds on top. Converts any amount between 31 major currencies using the European Central Bank daily reference rate — the neutral mid-market rate — and tells you the part every converter hides: the spread your bank or card will add on top of it. (tags: everyday, spending)
- [United States Income Tax Calculator (2026)](https://xearno.tools/t/income-tax-usa): 2026 United States income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes United States personal income tax for 2026 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [United Kingdom Income Tax Calculator (2025/26)](https://xearno.tools/t/income-tax-uk): 2025/26 United Kingdom income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes United Kingdom personal income tax for 2025/26 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [China Income Tax Calculator (2026)](https://xearno.tools/t/income-tax-china): 2026 China income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes China personal income tax for 2026 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [Japan Income Tax Calculator (2024)](https://xearno.tools/t/income-tax-japan): 2024 Japan income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes Japan personal income tax for 2024 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [Germany Income Tax Calculator (2025)](https://xearno.tools/t/income-tax-germany): 2025 Germany income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes Germany personal income tax for 2025 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [France Income Tax Calculator (2025)](https://xearno.tools/t/income-tax-france): 2025 France income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes France personal income tax for 2025 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [Canada Income Tax Calculator (2026)](https://xearno.tools/t/income-tax-canada): 2026 Canada income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes Canada personal income tax for 2026 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [Australia Income Tax Calculator (2025-26)](https://xearno.tools/t/income-tax-australia): 2025-26 Australia income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes Australia personal income tax for 2025-26 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [India Income Tax Calculator (FY 2025-26)](https://xearno.tools/t/income-tax-india): FY 2025-26 India income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes India personal income tax for FY 2025-26 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [Singapore Income Tax Calculator (2024)](https://xearno.tools/t/income-tax-singapore): 2024 Singapore income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes Singapore personal income tax for 2024 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [Hong Kong Income Tax Calculator (2024/25)](https://xearno.tools/t/income-tax-hong-kong): 2024/25 Hong Kong income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes Hong Kong personal income tax for 2024/25 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [Taiwan Income Tax Calculator (2025)](https://xearno.tools/t/income-tax-taiwan): 2025 Taiwan income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes Taiwan personal income tax for 2025 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [South Korea Income Tax Calculator (2024)](https://xearno.tools/t/income-tax-south-korea): 2024 South Korea income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes South Korea personal income tax for 2024 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [Vietnam Income Tax Calculator (2024)](https://xearno.tools/t/income-tax-vietnam): 2024 Vietnam income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes Vietnam personal income tax for 2024 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [Thailand Income Tax Calculator (2024)](https://xearno.tools/t/income-tax-thailand): 2024 Thailand income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes Thailand personal income tax for 2024 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [Indonesia Income Tax Calculator (2024)](https://xearno.tools/t/income-tax-indonesia): 2024 Indonesia income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes Indonesia personal income tax for 2024 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [Malaysia Income Tax Calculator (2024)](https://xearno.tools/t/income-tax-malaysia): 2024 Malaysia income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes Malaysia personal income tax for 2024 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [Spain Income Tax Calculator (2025)](https://xearno.tools/t/income-tax-spain): 2025 Spain income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes Spain personal income tax for 2025 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [Italy Income Tax Calculator (2025)](https://xearno.tools/t/income-tax-italy): 2025 Italy income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes Italy personal income tax for 2025 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [Netherlands Income Tax Calculator (2026)](https://xearno.tools/t/income-tax-netherlands): 2026 Netherlands income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes Netherlands personal income tax for 2026 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [Portugal Income Tax Calculator (2026)](https://xearno.tools/t/income-tax-portugal): 2026 Portugal income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes Portugal personal income tax for 2026 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [Brazil Income Tax Calculator (2024)](https://xearno.tools/t/income-tax-brazil): 2024 Brazil income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes Brazil personal income tax for 2024 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [Mexico Income Tax Calculator (2025)](https://xearno.tools/t/income-tax-mexico): 2025 Mexico income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes Mexico personal income tax for 2025 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)
- [Argentina Income Tax Calculator (2025)](https://xearno.tools/t/income-tax-argentina): 2025 Argentina income tax: tax owed, effective rate, marginal rate, and take-home pay. Computes Argentina personal income tax for 2025 using the official progressive brackets, and explains the number the way it actually works: your marginal rate versus your effective rate, how far you are from the next bracket, and exactly what this model excludes. (tags: earning, tax, planning)

## Xearno MBA Tools

- [Unit Economics](https://xearno.tools/t/unit-economics): LTV, LTV:CAC, and CAC payback — with the benchmarks that make them mean something. Computes customer lifetime value from ARPU, gross margin, and churn; compares it to acquisition cost; and reads the result against the standard SaaS/subscription benchmarks (3:1 LTV:CAC, sub-12-month payback). (tags: growth, finance)
- [Break-Even](https://xearno.tools/t/break-even): Units and revenue needed to cover costs — and how much pricing moves it. Classic cost-volume-profit analysis: contribution margin, break-even units and revenue, margin of safety if you supply current volume, and the leverage a price change has on all of it. (tags: finance, pricing, operations)
- [Runway & Burn](https://xearno.tools/t/runway): How many months of cash remain, and when to start raising. Computes runway from cash and net burn, optionally with burn trending up or down monthly, and reads the result against fundraising realities: raises take 3–6 months, and 18–24 months post-raise is the norm. (tags: funding, finance)
- [NPV & IRR](https://xearno.tools/t/npv-irr): Is this investment worth it — discounted, not vibes. Net present value, internal rate of return, payback period, and profitability index for a series of cashflows — the standard capital-budgeting toolkit, with the IRR pitfalls flagged instead of hidden. (tags: finance, strategy)
- [Pricing & Margin](https://xearno.tools/t/pricing-margin): Margin vs markup, and what a discount really costs in volume. Computes gross margin and markup from cost and price — two numbers people constantly confuse — and shows the brutal volume math behind discounting at your margin. (tags: pricing, finance)
- [Market Size (TAM · SAM · SOM)](https://xearno.tools/t/market-size): Bottom-up market sizing with a built-in plausibility check. Builds TAM, SAM, and SOM bottom-up from customer count and revenue per account, then sanity-checks whether the implied customer acquisition is actually plausible — the check most pitch decks skip. (tags: strategy, growth)
- [CAGR Calculator](https://xearno.tools/t/cagr): Compound annual growth rate — the honest average that volatile returns hide behind. CAGR between a start and end value over a period, plus the reverse projection — and why CAGR beats "average return" for judging any investment or revenue history. (tags: finance, growth)
- [ROI Calculator](https://xearno.tools/t/roi): Return on investment, simple and annualized — comparable numbers instead of raw bragging. Simple ROI from cost and final value, annualized when you give it a time period — because "we doubled our money" means something completely different over 2 years versus 12. (tags: finance, strategy)
- [VAT Calculator](https://xearno.tools/t/vat): Add or remove VAT at any rate — including the divide-not-subtract trap. Adds VAT to a net price or extracts it from a gross price at any rate. The extraction direction is where invoices go wrong: removing 20% VAT means dividing by 1.2, not subtracting 20%. (tags: tax, pricing, operations)
- [GST Calculator](https://xearno.tools/t/gst): Add or extract GST — India slabs (5/12/18/28), Australia/NZ/Singapore/Canada rates. GST both directions — exclusive to inclusive and back — with the Indian slab structure (5/12/18/28%) and the single-rate systems (Australia 10%, New Zealand 15%, Singapore 9%, Canada 5% federal) built into the rate picker. (tags: tax, pricing, operations)
- [Freelance Rate Calculator](https://xearno.tools/t/freelance-rate): The hourly rate that actually pays your target income — after unbillable time, overhead, and tax. Works backward from target income to the rate you must charge: subtracting non-billable time, business overhead, time off, and the self-employment tax gap that makes a freelance hour worth less than an employed one. (tags: pricing, earning)

## About

- Xearno Tools is part of Xearno (https://xearno.com), the fortune-themed personal finance app.
- Formulas and benchmark sources are documented on each tool page under Methodology.
- Tool schemas are stable and versioned; breaking changes get new versions.