Future value calculator

How savings grow

The future value of your savings has two parts: what you put in and what it earned. A starting amount grows by compounding, and each monthly deposit starts compounding from the month it is made. Early deposits have the most time to grow, which is why starting sooner matters more than depositing more later.

Worked example

Start with $1,000, add $100 at the end of every month, and earn 6% a year compounded monthly. After 10 years you have $18,207.33: $13,000 you contributed and $5,207.33 of growth.

Deposit at the start of each month instead, and every deposit earns one extra month: $18,289.27.

Saving $500 a month at 8% for 20 years, starting from zero, grows to about $294,510, of which only $120,000 is your own money.

Things to keep in mind

Investment returns are not fixed: a 6% average can include years of losses. Taxes, fees and inflation all reduce what you end up with. Use a conservative rate and treat the result as a guide.

The page uses the future value of a lump sum plus an ordinary annuity: starting amount × (1 + r)^m plus deposit × ((1 + r)^m − 1) ÷ r, with r the annual rate divided by 12 and m the number of months. If deposits are made at the start of each month, the annuity part is multiplied by (1 + r). Contributions are the starting amount plus all deposits; growth is the rest. Taxes, fees and inflation are not included.