64 tools · tested math · operator benchmarks
A bench of calculators for money and business decisions. Every tool computes the number, then reads it the way an experienced operator would — benchmarks, red flags, and the formula in the open. Built for people and for AI agents: same tools, same math, callable over API and MCP.
From the makers of Xearno, the app that treats your money as a living fortune rather than a spreadsheet. And because we make an app — not loans, cards, or leads — there are no ads here, no affiliate offers, and no reason for any number to steer you anywhere.
24 countries with current official brackets — tax owed, effective vs marginal rate, take-home pay.
taxincome24 countries
What a starting amount plus monthly contributions grows into over time.
investinginterest
The monthly saving needed to hit a target by a deadline.
budgetingplanning
Monthly payment, total interest, and what paying extra saves.
loansdebt
The portfolio that makes work optional, and how far away it is.
investingplanning
Even split with tip, rounded so nobody argues.
shopping
Which package is actually cheaper per unit.
shopping
What a gig actually pays per hour — after vehicle costs, waiting time, and self-employment tax.
gigincome
Turn an up-and-down income into a safe monthly salary and a right-sized buffer.
freelancegigbudgeting
How long your savings last after leaving a job — and whether new income overtakes costs before they run out.
freelanceplanning
Your exact retirement date under China’s 2025 delayed-retirement reform, plus an estimated monthly pension.
incomeplanning
Statutory severance under China’s Labour Contract Law — the N / N+1 / 2N branch and the 3×-average-wage cap, done right.
incomeplanning
Your real China take-home month by month — under the cumulative method, where the same salary is taxed more each month as the year goes on.
taxincome
What actually comes out of a China salary — and what the employer pays on top — with the contribution-base floor/ceiling applied correctly.
incometax
What is X% of Y, X is what percent of Y, and percent change — all three, correctly.
shopping
Sale price after one or two stacked discounts — and why 20% + 10% is not 30% off.
shopping
Tip, total, and per-person share — with actual tipping norms by region.
shopping
Convert between hourly, weekly, monthly, and annual pay at your real hours.
income
Time-and-a-half math: weekly gross with overtime, and your blended hourly rate.
income
What a raise is worth — and whether it beats inflation at all.
income
I = P·r·t — and how far it diverges from compound interest over time.
interest
Nominal vs effective rates — what a quoted APR really costs at your compounding frequency.
interestloans
What a price really costs you: hours of your own work, at your take-home pay.
shoppingincome
True monthly cost — principal & interest plus taxes, insurance, and PMI, not just the loan.
loanshome
Monthly car payment with down payment, trade-in, and sales tax — and the long-loan trap.
loansdebt
Loan EMI, total interest, and the flat-rate trap that makes 10% cost like 18%.
loans
Systematic Investment Plan returns — with optional annual step-up, honestly assumed.
investingplanning
How long your balance really takes to clear — and the minimum-payment trap in numbers.
debtbudgeting
How much house you can afford by the 28/36 rule — the underwriting math, honestly applied.
homeplanning
Convert between 31 currencies at the official ECB reference rate — and know what your bank adds on top.
shopping
LTV, LTV:CAC, and CAC payback — with the benchmarks that make them mean something.
pricingplanning
Units and revenue needed to cover costs — and how much pricing moves it.
pricingplanning
How many months of cash remain, and when to start raising.
budgetingplanning
Is this investment worth it — discounted, not vibes.
investingplanning
Margin vs markup, and what a discount really costs in volume.
pricing
Bottom-up market sizing with a built-in plausibility check.
planning
Compound annual growth rate — the honest average that volatile returns hide behind.
investing
Return on investment, simple and annualized — comparable numbers instead of raw bragging.
investing
Add or remove VAT at any rate — including the divide-not-subtract trap.
taxpricing
Add or extract GST — India slabs (5/12/18/28), Australia/NZ/Singapore/Canada rates.
taxpricing
The hourly rate that actually pays your target income — after unbillable time, overhead, and tax.
freelancepricing
Most calculator sites are lead-gen for lenders and advisors — the math frames the offer. We make an app, so the math has no side.
Every tool publishes its formula, assumptions, data basis, and what it deliberately excludes. Tested against worked examples; no silent changes.
Results come with the benchmark and the trap — the sentence an experienced operator would add after the figure.
Language models reason well and compute badly. Every tool here is a pure, deterministic, versioned function with a published JSON schema — an agent calls it instead of doing the arithmetic in its head, and gets back the values and the benchmark read to show its user.
curl -s https://xearno.tools/api/v1/tools/unit-economics \
-H 'content-type: application/json' \
-d '{"arpu": 50, "grossMargin": 80, "churn": 3, "cac": 400}'
{
"raw": { "ltvCacRatio": 3.3, "paybackMonths": 10, ... },
"insights": [
{ "level": "good",
"text": "3.3:1 sits in the healthy 3–5:1 range..." }
]
}