Percentages and Ratios

Calculate percent of a number, what percent one number is of another, reverse percentage, percentage change, and add or subtract a percentage.

Calculate percentage increase or decrease from an old value to a new value, including signed percent change, absolute difference, and multiplier.

Compare two peer values with symmetric percentage difference, absolute difference, average baseline, and larger-to-smaller ratio.

Calculate percent error between a measured or experimental value and an accepted value, with absolute error, signed relative error, and direction.

Find what a percent of a number is, such as 20% of 150, with quick percent presets and simple examples.

Find the whole number when you know that a part is a certain percent of it, such as 150 is 15% of what.

Find what percentage one number is of another, such as 30 is what percent of 200, with part, whole, and over-100% examples.

Add or subtract a percentage from a number and see the increase amount, decrease amount, and adjusted values.

Find how much more or less one number is than another using a directed base-value comparison.

Convert a percentage to decimal form, a simplified fraction, and a mixed number when the percentage is greater than 100%.

Find the percent of a number, then multiply the original number by that percentage amount for the exact N times P percent of N operation.

Divide a number by a percentage amount of that same number and see why the final coefficient depends only on the percentage.

Convert an annual interest rate to a periodic rate, or convert a known period rate back to an annual simple-rate equivalent on a 365-day basis.