I love financial calculators. But hey, I’m a finance geek. Not everyone wants, or needs, the level of complexity and detail available with professional financial calculators. Sometimes you want something nice and simple – like the free online investment returns calculator below.

FREE Online Investment Returns Calculator

Free online investment returns calculator

Some people might also call this a wealth accumulation calculator – since investments tend to be an important part of wealth accumulation for many people.

At its core, though it is an investment returns calculator. It forecasts investment growth over time based on the variables you provide.

Investment returns calculator inputs

Starting Amount

The investment returns calculator requires at least $100 as the starting amount. Hopefully, you already have this much or plan to invest at least this much fairly early. Even if your starting balance, in reality, is $0 the results will basically be the same. A starting amount of that size doesn’t impact the results nearly as much as the other factors.

Additional Contribution Amount

You can enter $0 into this part of the calculator if you don’t plan to invest on a regular basis. That would give you the results based on just the starting amount compounded over time.

Ideally, though you have some money set aside to invest every month. That investing practice is called dollar-cost averaging and it’s incredibly powerful. You can read our post on the Magic Math of Consistent Investing for more details.

By the way, don’t let a limited amount of available cash prevent you from investing. There are great solutions for investing small amounts of money too – and it really adds up over time.

If you have an amount allocated, or plan to, enter that in this field.

Additional Contribution Interval

This investment returns calculator allows for five different values on the additional contribution timing. You can choose from Weekly, Bi-Weekly, Monthly, Semi-Annually, and Annually.

Rate of Return

This is the average annual amount that you expect your investments to grow. How do you know what to enter? It really depends on how your investment portfolio is set up. Ours is all in stocks so we expect returns similar to, or better than, the S&P 500 index’s returns.

If you don’t know your own return, feel free to use the S&P 500 return. Many people consider this representative of “the market”. As of May 2017, the average annual return of the S&P 500 over the last 30 years has been 9.6%. I’ll update this article on occasion but you can get the S&P 500 returns yourself for different periods from this link if you want.

Years to Grow

This is pretty obvious. It should also be obvious that the longer you have money invested, the better it is going to grow.

Compounding is a powerful tool. Money compounding at 10% will double every 7 years. Your $5,000 today would be worth $40,000 in 21 years. $320,000 in another 21 years. Wow!

Investment returns calculator results

The results will tell you what your investments will be worth at the end of the length you entered, based on the data you provided.

It will also display a chart of the growth of the investments over time. Notice how the yellow line (earnings) gets bigger and bigger each year. That’s compounding at work!

Additionally, the investment returns calculator results will show you your starting amount, the total amount of any contributions you entered, and the total amount of earnings.

Free online investment returns calculator

Okay, now that you understand it, play around with it. Plug in the numbers from your plan (you DO have a plan, right?) and confirm the results. Then feel free to adjust any of the numbers to see how the results change.

This simple online calculator also works great as an investment goal calculator.

Adjusting the input variables is a great way to create different options to achieve your goals. Maybe you want to retire sooner? Change the values to see what higher return might be needed, or what higher monthly contribution amount it would take. Are you able to free up more money monthly? Make that adjustment to see how large of an impact it will have on your end results.


Here’s the calculator…