Enter two numbers and get the three answers people actually need: X% of Y, X is what % of Y, and the percent change from X to Y.
'X% of Y' reads X as a percent; the other answers read X and Y as plain numbers. General information only.
Most percentage math is one of three questions: what is X% of Y, what percent is X of Y, or how much did a value change. This does all three from the same two numbers.
X% of Y = X÷100 × Y · X is (X÷Y×100)% of Y · Change = (Y−X)÷X × 100
Subtract the old value from the new, divide by the old, and multiply by 100 — the "percent change" result above.
Going from 10% to 12% is a rise of 2 percentage points, but a 20% increase. They're not the same — keep them separate.
Related: percentage change calculator · markup calculator · discount calculator · all free calculators.
Yes. The Percentage Calculator is completely free, runs in your browser, and never asks for a signup, email, or download. Enter your numbers and the result updates instantly.
It uses standard formulas and recalculates the moment you change a value, so the math is exact for the inputs you enter. Treat the result as a reliable planning estimate; for decisions with legal or tax consequences, confirm the figures with a qualified professional.
Yes. The calculator is mobile-friendly and works on any phone, tablet, or computer — there is no app to install and nothing to save.
Yes. Scroll to “Add this free calculator to your site” above and copy the embed snippet to place the live calculator on your blog or website for free.
Last reviewed: September 2026. Free to use, no signup — Percentage Calculator by ToolWise Digital.
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