X% of Y, percent of a total, increase, decrease, and difference — all in one tool.
Percentage problems come in several genuinely different shapes — finding what X% of a number is, working out what percent one number is of another, or measuring how much something has grown or shrunk — and each needs a different calculation. Rather than making you remember which formula applies, this tool offers five explicit modes (X% of Y, X is what % of Y, % Increase, % Decrease, and % Difference), shows the formula it used, and gives the result instantly as you type.
Choose a mode — X% of Y, X is what % of Y, % Increase, % Decrease, or % Difference — enter your two values, then tap Calculate to see the formula and result.
What's the difference between % Increase and % Difference?
% Increase/Decrease measures change relative to the original value; % Difference measures the gap relative to the average of both values, useful when there's no clear "original".
Can I use negative numbers?
Yes, though results in Increase/Decrease mode are most meaningful when the original value isn't zero.