Investment Return Calculator
Project how an investment grows with a starting amount, monthly contributions and an expected return, with a year-by-year balance table.
Use this investment return calculator to project what a portfolio, savings account or retirement fund could be worth after a number of years. It combines a lump sum with regular monthly deposits, compounds the growth at the rate you choose, and splits the final balance into what you put in and what the investment earned.
How to use this tool
- Enter the amount you start with and what you plan to add each month.
- Enter the average yearly return you expect and how many years to invest.
- Choose how often returns compound and whether deposits go in at the start or end of the month.
- Optionally enter inflation to see the result in today's money.
Formula
FV = P × (1 + i)^n + C × ((1 + i)^n − 1) ÷ i
i = (1 + r ÷ m)^(m ÷ 12) − 1
P is the starting amount, C the monthly contribution, n the number of months, r the yearly return as a decimal and m the compounding periods per year. i is the equivalent monthly rate. Deposits at the start of the month multiply the contribution part by (1 + i).
Example
Start with $10,000, add $500 a month for 20 years and earn 7% a year compounded monthly. You contribute $130,000 in total and the balance grows to about $300,851, of which $170,851 is investment growth. At 2.5% inflation that is worth about $183,600 in today's dollars.
Frequently asked questions
What return should I use?
It depends on what you hold. Savings accounts pay roughly their quoted APY, bonds less than stocks, and broad stock indexes have historically averaged more but with large swings. Try a cautious and an optimistic rate to see a range.
Does compounding frequency matter much?
Less than people think. At 7%, monthly compounding gives an effective yearly rate of about 7.23% versus 7% for yearly compounding. The return itself and the number of years matter far more.
Are taxes and fees included?
No. Subtract expected fund fees from the return (for example, use 6.8% for a 7% return with a 0.2% fee) and remember taxable accounts may owe tax on gains.
This tool gives an estimate for general information only. It is not financial, tax, legal or medical advice — check with a qualified professional before you rely on the result.
Last updated: 2026-10-30