Compound interest formula
Without extra deposits: A = P(1 + r/n)nt. P is the start, r is the annual rate as a decimal, n is compounds per year, t is years. Extra monthly deposits are added each month before that month's growth. This is an estimate, not investment advice. Inflation and taxes are ignored.
Common questions
What compounding do savings accounts use?
Many high-interest savings accounts compound daily and pay monthly. Monthly is a fair default.
Does this include fees?
No. Subtract any account fee from the rate or the deposits if you want a closer picture.