Percentage change vs percentage difference
These two give different answers for the same numbers. Percentage change measures a move from an old value to a new one, so it divides by the old value. Going from 40 to 50 is (50 - 40) / 40 x 100 = a 25% increase. Use the percentage calculator for price rises, discounts and growth.
Percentage difference compares two values when neither is the starting point, so it divides by their average. For 40 and 50 that's 10 / 45 x 100 = 22.2%. The percentage difference calculator shows each step and also lists the plain change from A to B.
How the date and time tools count
The age calculator gives your age in years, months and days on today's date or any other. Days Between Dates shows two counts: exclusive, where the end day isn't counted, and inclusive, where both days are. From 1 March to 31 March that's 30 days exclusive and 31 inclusive. It also counts business days for a 4, 5, 6 or 7-day work week.
The time zone converter applies daylight saving time for the date you pick. The currency converter uses daily reference rates published by the European Central Bank, not live market prices.
Loan and BMI results are estimates
The loan calculator uses the standard amortization formula to show the monthly payment, total interest and a full schedule. A lender's quote can differ because of fees, insurance or how it rounds. The BMI calculator divides your weight in kilograms by your height in meters squared, and it uses the adult categories, where 18.5 to under 25 is the healthy range.
Both tools give estimates, not financial or medical advice.
Frequently asked questions
Are these online calculators free?
Yes. Every calculator and converter is free with no sign-up, and the calculations run in your browser.
How up to date are the currency rates?
They're daily reference rates from the European Central Bank, loaded through the Frankfurter API. Banks and card providers add a markup, so the converter lets you add a fee percentage to see what you'll pay.
Do QR codes made here expire?
No. The QR code generator makes static codes that store your link or text directly, so they keep working without our site.
Can I make a WiFi QR code?
Yes. Choose the WiFi type, enter the network name and password, and download the code as PNG or SVG. Phones that scan it can join the network without typing the password.
What's the difference between percentage change and percentage difference?
Percentage change divides by the starting value, so 40 to 50 is a 25% increase. Percentage difference divides by the average of the two values, so 40 and 50 differ by 22.2%.