What CalcWize is for
CalcWize helps you frame everyday financial and practical questions before you take them to a professional. Could you afford this house? How much would extra mortgage repayments save you over thirty years? Is your retirement plan on track? What does a 5% raise actually look like after tax? The calculators give you a clear set of numbers — a starting point you can take to a financial advisor, accountant, or mortgage broker for a real conversation.
Each calculator opens with a short explainer of what it's for, what assumptions it uses, and what it explicitly does not model. The point is to set expectations honestly: these are estimates, not advice. They're useful for planning, comparing, and pressure-testing — not for filing a tax return or signing a loan.
Money calculators
Seven tools cover the common money decisions: a monthly budget planner with the 50 / 30 / 20 rule built in, a loan / amortisation calculator with extra-payment modelling, a home affordability calculator that uses debt-to-income caps and country-specific property-tax assumptions, a compound-interest projector for long-term saving, a retirement planner with an inflation-adjusted "today's money" toggle, an income-tax estimator with current brackets for over twenty countries, and an investment ROI / CAGR calculator that lets you compare returns across different holding periods on equal footing.
- Monthly Budget Planner — Map your monthly income against spending categories to see where your money actually goes. Use this when you want to spot leaks, hit a savings target, or pressure-test the 50/30/20 rule against your real numbers.
- Loan Repayment Calculator — Calculate your exact monthly payment and watch the full payoff schedule unfold month by month. Use this before signing a loan, or to see how much interest you’d save by paying a little extra each month.
- Home Affordability Calculator — Estimate the maximum home price your income, deposit, and debt-to-income ratio actually support. Use this before house-hunting so you shop in a realistic price band — not one a lender simply approves you for.
- Compound Interest Calculator — Project how a starting balance plus monthly contributions can grow over time at a given interest rate. Use this to set savings goals, compare investment scenarios, or see why starting earlier beats saving more later.
- Retirement Planner — Estimate your nest egg at retirement and how long it’ll fund your lifestyle using a safe withdrawal rate. Use this to find out if you’re on track, and what to change (contributions, retirement age, target income) if you’re not.
- Income Tax Estimator — Apply your country’s tax brackets to your income to see what you owe and your effective vs marginal rate. Use this to plan ahead — sanity-check a payslip, model a raise, or compare scenarios across countries.
- Investment ROI Calculator — Measure the total return and annualised growth rate (CAGR) of any investment over its holding period. Use this to compare options on equal footing — a 60% return over 8 years isn’t the same as 60% in 2.
- salary.title — Convert an annual salary into monthly, weekly, and hourly pay, and apply an effective tax rate to estimate take-home. Use this to compare offers or see what an hourly rate really adds up to.
Car & vehicle calculators
Buying a car is one of the biggest everyday purchases there is. Four tools cover the whole decision: how much car you can afford on the 20/4/10 rule, the real cost of an auto loan, whether to lease or buy, and the true cost of ownership once depreciation and running costs are counted.
- car-affordability.title — Work out the car price you can actually afford using the 20/4/10 rule — 20% down, a 4-year loan, and all car costs under 10% of income. Use this before you set foot on a forecourt.
- auto-loan.title — Calculate the monthly payment, total interest, and amount financed on a car loan — including your deposit / down payment, trade-in, any tax, and dealer fees. Use this to sanity-check a finance offer.
- lease-vs-buy.title — Compare the true cost of leasing against financing the same car over the same period, accounting for resale value. Use this when a dealer pushes a lease and you want the honest number.
- car-cost-of-ownership.title — See what a car really costs once depreciation, fuel, insurance, maintenance, and registration are added up over the years you own it. Use this to compare cars on total cost, not sticker price.
Debt & savings calculators
Four tools for getting out of debt and building a cushion: compare debt-payoff strategies, see how long a credit card really takes to clear, plan toward a savings goal, and size the emergency fund that should come before everything else.
Conversion tools
Two converters for everyday cross-system maths: a currency converter that uses indicative reference rates for travel, shopping, or sizing up an offer in another currency, and a unit converter for length, weight, volume, temperature, time, and speed — recipes, DIY, travel, or any time someone hands you a number in the wrong system.
- Currency Converter — Convert amounts between major currencies using indicative reference rates. Use this for quick estimates while travelling, shopping, or sizing up an offer in another currency — not for booking a real trade.
- Unit Converter — Switch between length, weight, volume, temperature, time, and speed units in either direction. Use this for recipes, travel, DIY, or any time someone hands you a number in the wrong system.
Daily-life calculators
Three small tools you reach for outside of money: tip and bill-splitting (with an optional photo-scan mode for restaurant receipts), BMI in metric or imperial with the standard WHO categories, and a full keyboard-friendly scientific calculator with trig, logs, factorials, and exponentiation for homework or quick engineering checks.
- Tip Calculator & Bill Splitter — Calculate the tip on any bill and split the total evenly across the table. Use this to settle up at restaurants without arguing about the maths, or to set a consistent tip percentage as a personal default.
- BMI Calculator — Compute your Body Mass Index in metric or imperial and see which screening category it falls into. Use this as a rough first-look indicator only — it doesn’t measure body composition, and it’s no substitute for a clinician.
- Scientific Calculator — Run trig, logarithms, factorials, exponents, and the standard scientific functions with full keyboard support. Use this for homework, quick engineering checks, or any time the basic phone calculator runs out of buttons.
- percentage.title — Work out a percentage of a number, what percent one value is of another, and the percent change between two numbers — three of the most-searched everyday calculations in one place.
- age.title — Calculate your exact age in years, months, and days, the days until your next birthday, and the difference between any two dates. Use this for forms, anniversaries, and deadlines.
- sales-tax.title — Add sales tax or VAT to a price, or strip it out of a tax-inclusive total, to see the net amount, the tax, and the total. Use this for invoices, receipts, and quick shop maths.
- tdee.title — Estimate your daily calorie burn (TDEE) from the Mifflin–St Jeor BMR and your activity level, with targets for maintaining, losing, or gaining weight. A starting point, not medical advice.
Guides & reading
Want the ideas behind the numbers? These plain-English guides explain the concepts the calculators rest on — how loan amortisation works, why compounding rewards starting early, what the 4% rule really promises, how the main budgeting methods compare, and more.
- How Loan Amortisation Actually Works — Your loan payment never changes, but the split between interest and principal shifts every month. Here is why early payments feel like treading water — and how to fix it.
- Compound Interest: Why Time Beats Timing — Compound interest rewards patience more than cleverness. Here is how interest-on-interest works, why the last decade does the heavy lifting, and what quietly works against you.
- The 4% Rule, and the Case Against It — The 4% rule is the most quoted number in retirement planning. Here is where it came from, what it actually promises, and why many planners now treat it with caution.
- Five Budgeting Methods, Honestly Compared — There is no single best budget — only the one you will actually keep. Here are five popular methods, who each one suits, and where each one quietly falls apart.
- How Much House Can You Really Afford? — The maximum a bank will lend you is a ceiling, not a target. Here are the costs a mortgage payment hides and a saner way to set your own limit.
- Marginal vs Effective Tax Rates Explained — A raise into a higher tax bracket will not leave you worse off. Here is why brackets are marginal, what your effective rate really is, and when each number matters.
- Buying a Car: How to Get the Numbers Right — How to set a car budget, choose new vs used, finance sensibly, and weigh the true cost of ownership — without being steered by the monthly payment.
- Debt Snowball vs Avalanche: Which Pays Off Debt Faster? — The avalanche saves the most interest; the snowball keeps you motivated. Here is how each method works, when the gap actually matters, and how to choose.
- How Big Should Your Emergency Fund Be? — Three months, six, or twelve? How to size an emergency fund on your real essentials, where to keep it, and why it comes before investing or extra debt payments.
- Gross vs Net Pay: What Actually Lands in Your Account — Why your take-home is smaller than your salary, what the deductions are, and how to compare a salaried offer with an hourly rate on equal terms.
Privacy & how your data is handled
Every input you type into a CalcWize calculator stays in your browser's local storage on this device. There is no account, no server-side database, no analytics tracking individual values, and no cookie that follows you to other sites. If you clear your browser data, the saved scenarios go with it — that's the trade-off for not having a server holding them. The full details are in our Privacy Policy.
CalcWize displays Google AdSense advertising on calculator result pages to keep the tools free. Cookie consent is asked on first visit, and you can decline and continue using every calculator with no functional change beyond not seeing ads.
Translations
CalcWize is currently available in 21 languages including English, Spanish, French, Portuguese (Brazil), German, Dutch, Italian, Swedish, Romanian, Bulgarian, Russian, Ukrainian, Korean, Japanese, Mandarin Chinese (simplified and traditional), Cantonese, Indonesian, Malay, Thai, and Hindi. The interface translations are in beta — you can switch language from the topbar at any time. The long-form explainer pages on each calculator are now also available in all supported languages.
Not financial advice
CalcWize provides estimates only. Tax brackets, indicative FX rates, simplified retirement assumptions, and other inputs are designed to spark useful conversations — not to replace professional advice. For any consequential decision (buying a home, planning retirement, restructuring debt, filing a tax return), please speak with a qualified financial advisor, accountant, or licensed tax preparer in your jurisdiction.