Calculate percentages, simple interest, and compound interest entirely in your browser with EverydayKit’s free calculator. Find X% of Y, reverse percentages, percent change, and growth on principal with flexible compounding—no signup and no data leaves your device.
Frequently asked questions
What can this calculator do?
It covers three modes: percentage math (X% of Y, reverse %, and percent change), simple interest, and compound interest with annual through daily compounding.
How is simple interest calculated?
Simple interest uses I = P × r × t, where P is principal, r is the annual rate as a decimal, and t is time in years. The total is principal plus interest.
How is compound interest calculated?
Compound interest uses A = P (1 + r/n)^(n×t). You choose how many times interest compounds per year (annually, monthly, daily, and more).
Is my data stored?
No. All calculations run client-side. Nothing you type is sent to a server or saved by EverydayKit.
Can I use this for loans or investments?
Yes for quick estimates. For legal or financial decisions, confirm figures with a qualified advisor or your lender’s official amortization schedule.