Interest earned on both the original money and the interest already added. Growth speeds up over time because each new interest payment starts earning too.

No. The calculator assumes one steady rate. Savings rates can change, and investments can lose value.

It can. Monthly compounding adds interest more often than yearly compounding, so the balance grows a little faster at the same yearly rate.

Regular deposits often matter more than people expect, because each one starts earning right away. Try both inputs in the calculator to compare.

No. Taxes on interest and the effect of rising prices on what your money can buy are not included. Both can make the real result smaller.