Free Online Calculators
Every calculator here shows the formula and the numbers behind its result, so you can check the answer instead of taking it on trust. Search for what you need, or browse the categories below.
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34 calculators01Health
5 calculators- BMI CalculatorEnter your weight and height to calculate your Body Mass Index (BMI), a quick screening measure used worldwide to estimate whether your weight falls in a healthy range for your height.Shows its formula3 figures checked · 2026-08-13
- Body Fat Percentage CalculatorWith your height, neck, waist, and (if female) hip measurements, this calculator estimates your body fat percentage using the U.S. Navy circumference method — no calipers or scans required, just a tape measure.Shows its formula1 figures checked · 2026-08-14
- TDEE CalculatorEnter your sex, age, weight, height, and activity level to estimate your Total Daily Energy Expenditure (TDEE) — the number of calories your body burns in a typical day, including movement and exercise.Shows its formula
- Due Date CalculatorEstimates your due date, trimester and full-term dates from your last period and cycle length. Not a substitute for medical care.Shows its formula2 figures checked · 2026-08-22
- Ovulation & Fertile Window CalculatorFrom the start date of your last period and your typical cycle length, this calculator estimates your ovulation date, your fertile window, and your next expected period.Shows its formula2 figures checked · 2026-08-22
02Finance
20 calculators- Loan Payment CalculatorTwo loan offers can show the same monthly payment and still differ by tens of thousands in total interest. This calculator shows both, plus how the balance falls year by year.Shows its formula
- Compound Interest CalculatorInterest that earns interest bends the curve upward. See how far a starting amount plus monthly savings can travel, and how much of the finish line is growth rather than deposits.Shows its formula
- Retirement Savings CalculatorEstimate how your current savings and monthly contributions could grow by retirement — and what that amount is actually worth once inflation is factored in.Shows its formula
- Korea Salary Take-Home Pay CalculatorA Korean job offer is quoted as an annual figure, and roughly a tenth to a fifth of it never reaches your account. This calculator rebuilds the four social insurance premiums and the withheld income tax that stand between the two numbers, month by month.Shows its formula10 figures checked · 2026-08-12
- Japan Take-Home Pay Calculator (Tedori)Enter your annual salary, age, prefecture, industry and dependents to estimate your monthly take-home pay (tedori) in Japan, including the four social insurance premiums, withheld income tax, and resident tax.Shows its formula9 figures checked · 2026-08-12
- Germany Salary Calculator (Brutto-Netto-Rechner)Two colleagues on the same €60,000 contract can take home noticeably different amounts, because tax class, church tax, children and the health fund you belong to all move the figure. This calculator works through the 2026 German payroll chain to show what actually reaches your account each month.Shows its formula11 figures checked · 2026-08-12
- Spain Salary Calculator (Nómina Bruto a Neto)Enter your gross annual salary, contract type, region, age bracket, and number of children to estimate your monthly net pay (salario neto) in Spain for 2026.Shows its formula10 figures checked · 2026-08-12
- Korea Import Duty CalculatorEnter the item price, shipping cost, origin, and duty rate to estimate customs duty and VAT for a shipment to Korea. Look up the duty rate for your specific item at Korea Customs before entering it.Shows its formula5 figures checked · 2026-08-22
- Korea Severance Pay CalculatorKorea pays statutory severance to anyone who completes a year of continuous service, whether they resign or are let go. This works out what that comes to for your dates and wages.Shows its formula3 figures checked · 2026-08-12
- US Mortgage Calculator (PITI)Enter your home price, down payment, rate, and term to estimate your total monthly payment — principal, interest, property tax, insurance, PMI, and HOA — and see exactly when PMI is scheduled to end.Shows its formula4 figures checked · 2026-08-12
- Jeonse to Wolse Conversion CalculatorEnter your jeonse deposit and the rate your landlord is offering to see the monthly rent it produces — and instantly check whether that rate is within Korea's legal cap on deposit-to-rent conversion.Shows its formula5 figures checked · 2026-08-12
- Rent vs Buy CalculatorEnter what you'd pay to buy and what you'd pay to rent, and see in which year owning pulls ahead — accounting for transaction costs and the investment return you give up.Shows its formula
- Extra Mortgage Payment CalculatorAdd an extra amount to each payment, or a lump sum today, and see how many months it cuts off your loan and how much interest it saves.Shows its formula
- Stock Average Price CalculatorEnter what you already hold and what you're about to buy, and see the new weighted-average cost per share, the total money invested, and how far the price needs to move to break even.Shows its formula
- Dividend Tax Calculator (After-Tax Amount)Enter your dividend per share and the number of shares you hold, choose a country, and see the withholding tax and after-tax amount using rates confirmed for 2026.Shows its formula6 figures checked · 2026-08-19
- VAT CalculatorEnter an amount and whether it includes VAT to get the net, tax, and total. Pick a country’s rate or enter your own.Shows its formula4 figures checked · 2026-08-19
- UK Take-Home Pay CalculatorTwo people holding the same £45,000 offer can bank noticeably different amounts once PAYE, a workplace pension and a student loan plan are applied to it. This calculator works out what actually reaches your account in the 2026/27 tax year, for England, Wales and Northern Ireland.Shows its formula4 figures checked · 2026-08-19
- Australia Take-Home Pay CalculatorAustralian pay is negotiated as an annual package but arrives weekly or fortnightly, and the gap between the two numbers is where residency status, the Medicare levy and a study debt quietly do their work. This calculator shows both figures for the 2026-27 financial year.Shows its formula8 figures checked · 2026-08-19
- Canada Take-Home Pay Calculator (2026)The same salary pays differently in Alberta and Ontario, because Canada stacks a provincial tax table on top of the federal one. Pick a province and this calculator works through both layers, plus CPP, CPP2 and EI, to reach a 2026 take-home figure.Shows its formula7 figures checked · 2026-08-19
- UK Stamp Duty Calculator (SDLT)Enter the purchase price and buyer type to estimate Stamp Duty Land Tax (SDLT) for England or Northern Ireland — calculated band by band, not as one rate on the whole price.Shows its formula5 figures checked · 2026-08-19
03Math
1 calculators04Everyday
8 calculators- Date Difference CalculatorHow many days lie between two dates? This calculator counts them in whole days, converts the total into weeks and into approximate months and years, and reports separately how many of those days fall Monday to Friday.Shows its formula1 figures checked · 2026-08-12
- Age CalculatorHow old is someone on a given day, counted the way an official form counts it? This calculator answers in completed years, months and days, and adds the total number of days lived and the date of the next birthday.Shows its formula
- Unit ConverterConverts length, weight, area, volume, and temperature between metric and customary units, using exact defined factors.Shows its formula
- Tip CalculatorWork out what a table owes once the tip is on top. Give the bill, the percentage and the headcount, and the calculator returns the tip, the total and each share, with the option to round up either the total or the individual amounts.Shows its formula
- Discount CalculatorTwo discounts stacked on one item are not the sum of the two percentages. Put in the original price and both offers to see the final price, the amount saved, and the effective rate the stack really works out to.Shows its formula
- Korea Paid Annual Leave CalculatorKorean paid leave runs on two separate tracks, and which one governs your year depends on how long you have been employed. This tool works out where you stand on any date you pick.Shows its formula3 figures checked · 2026-08-12
- Korea Weekly Holiday Pay CalculatorKorean law pays for one rest day a week on top of the hours you actually work. This works out what that allowance adds to your pay at your hourly rate.Shows its formula4 figures checked · 2026-08-19
- Split Bill CalculatorWho owes what when one bill covers a table? Give the total, the headcount, and how many people are paying nothing or half, and the calculator returns each share plus the surplus that rounding up quietly collects.Shows its formula