Investment Calculator

It applies a growth formula to your inputs. With a compounding rate, the formula is final value = amount x (1 + rate / periods) ^ (periods x years). With a simple rate, interest is earned only on your original amount. With a dollar amount, it compares what you put in with what you got back. Our calculator shows the steps as a chart and a period-by-period table you can export.

That depends on the rate and how long you leave it alone. At 7% compounding monthly, $10,000 grows to about $20,097 in 10 years, $40,387 in 20 and $81,165 in 30. Those are math, not promises. Change the rate to a lower number too, because a realistic range tells you more than one optimistic figure.

The math is exact, but the inputs are guesses. A calculator can't know your future return, so its answer is only as good as the rate you type. It also assumes steady growth, while real returns jump around year to year, and it leaves out fees and taxes unless you account for them. Use it to compare scenarios, and rerun it with a lower rate to see how much room for error you have.

It depends on the risk you take. Savings accounts and government bonds pay modest, relatively safe returns, while stocks have paid more over long periods with big swings along the way. Many long-term plans assume somewhere around 6% to 7% a year for a stock-heavy portfolio, though no return is guaranteed. A good return is one that beats inflation and your other options for the same risk.

Most investments aren't judged monthly because a month's result is mostly noise. If you want the math, a 7% yearly return works out to about 0.57% a month when compounded. Be wary of anyone promising a steady 2% or 3% every month. Compounded, that would be 27% to 43% a year, which is a common sign of a scam.

A common benchmark is to save about 15% of your income for retirement, counting any employer match, but your debts, emergency savings and goals all matter. To see the effect of a monthly habit, use the 401(k) calculator or the Roth IRA calculator, which both model regular contributions. This page models a single lump sum.

Subtract what you put in from what you ended up with, then divide by what you put in. Buying something for $5,000 and ending with $6,000 gives a $1,000 gain and a 20% ROI. Count fees and other costs as part of what you put in. If you want the same answer without the arithmetic, use the simple ROI calculator.

ROI is your total gain over the whole period, however long that was. The effective annual rate tells you what that gain works out to per year, including compounding. A 50% ROI sounds the same whether it took two years or twenty, but the yearly rate is about 22.5% in the first case and about 2.0% in the second. Use the yearly rate to compare investments held for different lengths of time.

The rule of 72 gives a quick estimate: divide 72 by your yearly return. At 6% that is about 12 years, and at 9% about 8 years. The exact figure for 9% compounding monthly is 7.7 years. Try it above by setting a rate and changing the time until the final value is twice your amount.

No. Results are before taxes, fees and inflation unless you adjust the inputs. To approximate them, lower your rate. A 7% return with a 0.5% yearly fee is about 6.5%, and subtracting expected inflation of 2.5% gives roughly 4% in today's purchasing power. Tax depends on your account type and income, so check IRS rules or a tax professional for your situation.

Run each one with the same amount and the same time period, then compare the effective annual rate and not the headline ROI. Add every fee you can find, and ask how much of the return is guaranteed. Copy the link for each result so you can reopen both later. A higher number with far more risk is not automatically the better choice.