Free online converters and calculators
Convert anything.
Calculate anything.
Fast, accurate calculators and converters for everyday life. One calm place for all the numbers that matter.
START WITH A TOOL
Ten tools for the numbers in your day.
Each opens a dedicated page built around one clear calculation.
Currency Converter
Convert between world currencies using dated exchange rates.
Percentage Calculator
Calculate percentages, increases, decreases and differences.
Age Calculator
Find your exact age in years, months, days and more.
Unit Converter
Convert length, area, volume, speed, energy, pressure and more.
Weight Converter
Convert mass between kilograms, pounds, ounces, stones and more.
Temperature Converter
Convert Celsius, Fahrenheit and Kelvin temperatures.
Date Calculator
Date difference, add or subtract days, business days and countdown.
Time Zone Converter
See the same instant in any world time zone, with a world clock.
Fuel Cost Calculator
Estimate fuel needed and trip cost from distance and consumption.
Discount Calculator
Find the final price after a discount, or reverse to the original.
Days From Today Calculator
Find the date any number of days or business days from today or another date.
Christmas Countdown
A live countdown to Christmas Day in days, hours, minutes and seconds.
TDEE Calculator
Estimate the calories you burn each day from your BMR and activity level.
MOST SEARCHED
Popular conversions and calculators.
Jump straight to the answer people look for most, from kilometers to miles and euro to dollar to mortgage payments and US time zones.
Distance and speed
Loans, pay and tax
Engineering units
Everyday answers
Time zones and population
SIMPLE ON THE OUTSIDE
How it works.
Pick a tool
Choose a dedicated calculator or converter, or type what you need into the search.
Enter your values
Every input is clearly labelled. Swap, reset and copy are right where you need them.
Get a clear answer
The result appears instantly, with the formula and context you need to trust it.
BUILT FOR TRUST
Powerful on the inside, clear on the page.
No accounts, no clutter, no mysterious math. Just useful tools with sensible precision and the context you need.
Explore every toolReal standards
ISO 4217 currencies, the IANA time zone database, and internationally recognised unit definitions — never invented numbers.
Transparent formulas
Every result shows the method behind it, so you can verify any figure before you rely on it.
Honest about data
When live exchange rates are unavailable, we say so clearly — we never fabricate a rate to fill the page.
GOOD TO KNOW
Frequently asked questions.
Are these converters and calculators free?
Yes. All 77 tools are free to use, with no sign-up and no limit on how many calculations you run. The site is funded by advertising.
How do I convert km to miles?
Multiply kilometers by 0.621371. For example, 100 km = 62.14 miles and 50 km = 31.07 miles. The km to miles converter has a full table from 1 to 1,000 km.
Where do the exchange rates come from?
The converter uses Coinbase’s public exchange-rate service, fetched by your browser when you open a currency page, and shows the time of the rate with every result. The amount tables on the pair pages use the European Central Bank’s daily euro reference rates, with their date.
How accurate are the unit conversions?
They use exact international definitions, such as 1 inch = 2.54 cm and 1 pound = 0.45359237 kg, so the only rounding is the number of decimals you choose to show.
Is what I type stored anywhere?
No. Calculations run in your browser. Favorites and saved calculations are kept only in your browser’s local storage, if you choose to use them.
Can I rely on the loan and tax results?
They are careful estimates using standard formulas, but lenders, tax rules and fees vary. Confirm important figures with your lender, the tax authority or a professional.