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These calculators answer one everyday question each and show how they got there. The Percentage Calculator has five tabs: X% of Y, X is what % of Y, change from X to Y, difference between X and Y, and add or subtract a %. Each answer comes with its formula in words and the working with your numbers in place, so you can check it by hand: 15% of 80 is 12, and the change from 80 to 100 is +25%. The Age Calculator gives an age in years, months and days on any date you choose, with the next birthday and the weekday of birth, and the same tool works out the years, months, days and total days between two dates for a notice period, a lease or a trip. It counts whole calendar months first, then the days left over. The Aspect Ratio Calculator reduces a width and height to a ratio, so 1920 by 1080 is 16:9, or finds the missing width or height for 16:9, 4:3, 9:16 or a ratio of your own, with the rounding shown.
The numbers and dates you enter stay in your browser tab and are not sent to a server. For units, time zones and colours see the converters.
Subtract the starting value from the new value, divide by the starting value and multiply by 100. From 80 to 100 that is 20 divided by 80, which is +25%. The Percentage Calculator shows these steps under the answer.
The percentage difference compares two values when neither is the starting point, so it divides by their average. 80 and 100 differ by 22.222222%, while the change from 80 to 100 is +25%. The calculator has a separate tab for each.
It counts whole calendar months first, then the days left over. 15 June to 15 July is one month whatever the length of June, and 31 January 2023 to 28 February 2023 is exactly 1 month and 0 days.
16:9. Both sides divide by 120, giving 16 and 9, and the decimal form is about 1.778 to 1. The Aspect Ratio Calculator also finds the missing side, for example a height of 720 for a width of 1280 at 16:9.