Eighteen calculators covering finance (loan, mortgage, interest, savings, VAT, tip, discount), business (ROI, break-even, profit margin, salary tax), health (BMI, calorie), lifestyle (age, fuel cost, GPA) and general utility (percentage, unit converter). Each one runs instantly in your browser as you type — no submit button, no waiting, no ads in the calculation flow. This guide explains which calculator solves which real-world question, and how to combine them for planning decisions.
Work out what to charge with VAT on top, or pull the VAT back out of a gross price — the two calculations freelancers and shoppers actually need.
Solve the three percentage questions people actually get stuck on: X% of Y, what percent X is of Y, and the change from X to Y.
See what a '30% off' sticker actually means — how much you save and what you pay at the till.
Find out what a personal, car or student loan will cost you per month — and how much of it is interest, not principal.
See what a savings pot or investment actually grows to — and how much of that is simple interest versus compounding.
Work out someone's exact age in years, months and days — for forms, eligibility checks and 'how old is grandma really?' moments.
Get your BMI and the WHO weight category from your height and weight — the same number your doctor's chart uses.
Turn a gross salary offer into the number that actually lands in your bank account — annually and monthly.
See what a house at a given price actually costs each month — and how much you'll pay in interest over 15 vs 30 years.
Sort a restaurant bill: pick a tip percentage, split by the number of people, and see what each person owes.
Calculate your break-even point
Calculate profit margin and markup
Calculate return on investment
Calculate your grade point average
Calculate daily calorie needs
Convert between units of measurement
Calculate fuel costs for trips
Calculate savings growth over time
Buying a home: start with the Mortgage Calculator for the monthly payment, then use the Loan Calculator to compare a smaller loan for the down payment, and the Savings Calculator to plan how quickly you can rebuild savings. Evaluating an investment: ROI Calculator for expected return, Interest Calculator for compound growth over time, Savings Calculator to model steady contributions. Running a business? Break-Even Calculator tells you the units to sell, Profit Margin Calculator sets the price, VAT Calculator adds tax correctly for the region.
BMI Calculator gives a rough weight-for-height signal but ignores muscle mass and body composition — treat it as one data point, not a verdict. Calorie Calculator uses the Mifflin-St Jeor equation, one of the most accurate formulas for basal metabolic rate; multiply by an activity factor for daily needs. Age Calculator returns exact years, months and days, useful for legal, medical or milestone contexts.
Percentage Calculator handles the three common variants: 'what is X% of Y', 'what percent is X of Y', and 'percent change from X to Y'. Discount Calculator answers 'what's the final price after this deal'. Tip Calculator splits a bill including or excluding the tip, useful for group dinners. Unit Converter covers length, weight, temperature, volume and area — no more googling 'how many ounces in a cup'.
The maths is exact — floating-point precision is not a limitation at everyday scales. What varies is the model behind the calculation: tax rates change by country and year, mortgage amortisation assumes fixed rates, BMI ignores body composition. Every calculator uses standard, published formulas, but you should still cross-check any high-stakes decision (loan approval, tax filing) with a professional or an official calculator from your local authority.
There's no submit button — every field is reactive. This lets you explore scenarios quickly: nudge the interest rate up 0.5% to see the monthly payment impact, change the term from 30 to 25 years, drop the tip from 20% to 15%. This 'live modelling' approach makes the calculators genuinely more useful than a static formula.
The maths is exact. Any variance comes from the underlying model — for example, mortgage calculators assume a fixed rate and don't include insurance or property tax. Use the results as an accurate starting point, not a final answer for legal or tax decisions.
No. All calculations run in your browser. Nothing is saved, uploaded, or logged.
No. Every calculator is free and unlimited without a signup.
Once the page has loaded, yes — the calculation runs entirely in your browser, so you can disconnect and it still works.
Yes. All calculators are fully responsive and are actually used more on mobile than desktop for quick everyday calculations.