How will my investment grow?
Enter what you have now, what you add, and a yearly return. See the final balance, how much is your money, and how much is growth.
- You’ll have
- $292,465.03
Putting in $130,000.00 over 20 years at 7% a year grows to $292,465.03, of which $162,465.03 is growth.
- Your money
- $130,000.00
- Contributions
- $120,000.00
- Growth
- $162,465.03
- In today’s moneyIf prices rise by the inflation rate each year
- $161,930.80
- Months
- 240
You’ll have: $292,465.03. Putting in $130,000.00 over 20 years at 7% a year grows to $292,465.03, of which $162,465.03 is growth.
How much of it is growth?
How does it grow?
What does each year look like?
The results are estimates for information only. They are not financial, tax, or legal advice. Check the numbers with your lender or a qualified professional before you decide. Terms of use
How to calculate
Computes what a starting amount plus regular monthly or yearly contributions grows to at a fixed yearly return, and how much of it is growth.
Example with the default inputs (Starting amount $10,000.00, Contribution $500.00, How often do you add it? Monthly, Expected yearly return 7%, For how long? (years) 20, Contributions are added at the End of the period, Raise contributions each year by 0%, Prices rise each year by 3%): Putting in $130,000.00 over 20 years at 7% a year grows to $292,465.03, of which $162,465.03 is growth.
Method: Each month the balance grows at the monthly rate (1 + R)^(1/12) − 1, where R is the yearly return; contributions are added at the start or end of each month (monthly) or of each year (yearly).
- The yearly return stays the same every year. Real returns go up and down, and can be negative.
- Growth compounds monthly at the rate that gives exactly the yearly return over 12 months.
- A raise applies from the start of year 2, and again each year after.
- No fees or taxes are taken out, unless you lower the return to allow for them.
- “In today’s money” divides the final balance by (1 + inflation)^years.
- This is an estimate for planning, not financial advice.
Worked examples
Each example is checked against the calculator on every build.
- Starting amount $20,000.00, How often do you add it? Monthly, Expected yearly return 7%, For how long? (years) 10, Contributions are added at the End of the period, Prices rise each year by 3% gives You’ll have $39,343.03, Growth $19,343.03, In today’s money $29,274.91.Source: hand calculation in content.mdx: 20,000 × 1.07^10 (SEC Investor.gov compound interest formula)
- Starting amount $0.00, Contribution $500.00, How often do you add it? Monthly, Expected yearly return 6%, For how long? (years) 30, Contributions are added at the End of the period gives You’ll have $487,256.49, Your money $180,000.00, Growth $307,256.49.Source: future value of an annuity, hand calculation in content.mdx
- Starting amount $1,000.00, Contribution $6,000.00, How often do you add it? Yearly, Expected yearly return 5%, For how long? (years) 3, Contributions are added at the Start of the period gives You’ll have $21,018.38, Contributions $18,000.00.Source: hand calculation in content.mdx: 1,000 × 1.05³ + 6,000 × (1.05³ + 1.05² + 1.05)
- Starting amount $0.00, Contribution $100.00, How often do you add it? Monthly, Expected yearly return 0%, For how long? (years) 2, Contributions are added at the End of the period, Raise contributions each year by 10% gives You’ll have $2,520.00, Your money $2,520.00, Growth $0.00.Source: hand calculation in content.mdx: 12 × 100 + 12 × 110
How the balance is worked out
The calculator runs month by month for the number of years you choose. The yearly return R (as a decimal) becomes a monthly rate:
g = (1 + R)^(1/12) − 1
so 12 months of growth equal exactly one year at R.
Each month:
- Contribution at the start (if you picked "Start of the period" and money is added this month): add it first, then growth = (balance + contribution) × g.
- Contribution at the end (the default): growth = balance × g, then add the contribution.
When money is added:
- Monthly: every month.
- Yearly: once a year, in the first month of each year (start) or the twelfth month (end).
Raise. The contribution in year k (k = 1, 2, 3, …) is contribution × (1 + raise)^(k − 1). An empty raise counts as 0%.
The results:
- You’ll have is the balance after the last month.
- Your money is the starting amount plus every contribution. Contributions leaves out the starting amount.
- Growth is the balance minus your money.
- In today’s money is the balance ÷ (1 + inflation)^years. It is left out when the inflation rate is empty.
Assumptions
- The return is the same every year. Real returns vary and can be negative.
- No fees or taxes are taken out.
- This is an estimate for planning, not financial advice.
Worked examples by hand
$20,000 left alone at 7% for 10 years. 20,000 × 1.07^10 = 20,000 × 1.967151 = $39,343.03, so the growth is $19,343.03. At 3% inflation, in today’s money it is 39,343.03 ÷ 1.03^10 = 39,343.03 ÷ 1.343916 = $29,274.91.
$500 at the end of every month at 6% for 30 years, from $0. g = 1.06^(1/12) − 1 = 0.0048676, and (1 + g)^360 = 1.06^30 = 5.743491. FV = 500 × (5.743491 − 1) ÷ 0.0048676 = 500 × 974.5130 = $487,256.49. You put in 360 × 500 = $180,000.
$1,000 today plus $6,000 at the start of each year at 5% for 3 years. The $1,000 grows for 3 years, and the three $6,000 amounts grow for 3, 2, and 1 years: 1,000 × 1.157625 + 6,000 × (1.157625 + 1.1025 + 1.05) = 1,157.63 + 19,860.75 = $21,018.38.
$100 a month raised 10% a year, 0% return, 2 years. Year 1: 12 × $100 = $1,200. Year 2: 12 × $110 = $1,320. Total $2,520, all your money.
Other questions people ask
What yearly return should I enter?
Nobody knows future returns. Investments such as stock funds rise and fall from year to year, and some years they lose money. The calculator uses one fixed rate for every year, so treat the result as one possible path. Try a low, a middle, and a high rate to see a range, and compare the results.
Why is a 7% yearly return not 7 ÷ 12 per month here?
The calculator uses the monthly rate that compounds to exactly the yearly return: (1 + 0.07)^(1/12) − 1 = 0.5654% a month. Twelve months at that rate give exactly 7%. Using 7 ÷ 12 = 0.5833% a month would give 7.23% a year instead.
Does it matter if I add money at the start or the end of the month?
A little. Money added at the start of a period grows for that whole period, so the final balance is higher. With $500 a month at 6% for 30 years, adding at the start gives about $2,370 more than adding at the end. You can switch this under "Timing, raises and inflation".
What does "in today’s money" mean?
Prices usually rise over time, so a dollar in 20 years buys less than a dollar today. "In today’s money" divides the final balance by (1 + inflation) for each year. At 3% inflation, $100,000 in 20 years buys about what $55,368 buys today.
Are fees and taxes included?
No. The calculator adds growth at the rate you enter and takes nothing out. Fund fees and taxes lower what you keep. To allow for a fee, lower the return by it: a 7% return with a 0.5% yearly fee is roughly a 6.5% return.
How is this different from the compound interest calculator?
The compound interest calculator is for savings with an interest rate and a compounding choice (monthly, quarterly, yearly). This investment calculator uses a yearly return, lets you add money once a year or every month, at the start or the end, and raise the amount each year.
Is this financial advice?
No. It is a calculator that shows the arithmetic of steady growth. It cannot tell you what to invest in or what return you will get.