Compound interest uses A = P x (1 + r/n)^(n x t), where P is the starting amount, r is the annual rate as a decimal, n is how many times a year it compounds, and t is the number of years. A free compound interest calculator runs the formula in your browser with no signup, so you can try any amount, rate and period instantly.
Free compound interest calculator. See how savings grow with regular contributions, compounding frequency, rate and time, plus interest earned instantly.
Open Compound Interest Calculator → Free toolFree investment and savings calculator. Project the future value of an initial deposit plus recurring contributions at a given annual return over time.
Open Investment / Savings Calculator →The end balance is A = P x (1 + r/n)^(n x t). As an example only, 1,000 invested for 10 years at an example rate of 5 percent compounded monthly is 1,000 x (1 + 0.05/12)^(12 x 10), which works out to about 1,647.01. The interest earned is the balance minus the 1,000 you started with, so about 647.01. These rates are illustrations, not a promised return.
The more often interest compounds, the more you earn, because each new interest payment itself starts earning. Using the same example 1,000 at 5 percent over 10 years, annual compounding gives about 1,628.89 while monthly gives about 1,647.01. The gap is small over one decade but widens with higher rates and longer horizons, which is the whole point of starting early.
Simple interest is charged only on the original principal, while compound interest is charged on the principal plus the interest already accumulated, so it grows faster over time.
About 1,647.01, using the example rate of 5 percent. The interest portion is roughly 647.01 on top of the 1,000 principal.
Yes, but with diminishing returns. Moving from annual to monthly helps; moving from monthly to daily adds very little at typical rates.