Monthly investment growth

See how regular monthly investing might grow if you increase contributions each year.

Your inputs

About this calculator

See how regular monthly investing might grow over time.

Your information

Enter your best estimates below.

What you have invested today.
Amount you add every month.
How long you keep investing.

How we run the estimate

Change return and inflation below. Balances, contributions, and timeline stay in the panel above.

Average yearly growth — markets will vary.
8.0%
2.5%
When contributions count
Added at the end of each month
Raises to your monthly amount
None — same contribution every year
Not included
Taxes, account fees, and year-to-year market ups and downs

Your results

Projected balance

Future balance at year 20

$331K

Total invested: $130,000. Growth from returns: $201,109.11.

Total contributions

$120K

Investment growth

$201K

Balance growth over time

  • Projected balance
  • Total you invested
1234567891011121314151617181920Year$0$85K$170K$255K$340K

Invested vs. growth breakdown

Total investedGrowth from returns$0$55K$110K$165K$220K

Beyond this calculator

Investment growth is not a retirement spending plan

This chart projects compounded monthly investing without taxes or fees. A complete Retirelens plan also maps:

  • When you will need the money and how you plan to spend it
  • Taxes on gains in taxable accounts
  • Employer match and tax-advantaged account choices
  • Increasing savings as income grows

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Interpretation

What this means

Planning context for the estimates above. Not tax, legal, or investment advice.

Investing $500/month for 20 years at 8% annual return could grow to about $331,109.11.

Of that total, $130,000 came from your own contributions (starting balance + monthly contributions) and $201,109.11 came purely from investment returns — showing the power of compounding over time.

Methodology

How this calculator works

The rules and math behind this estimate.

Returns are compounded monthly. Contributions are added at the end of each month. Taxes, fees, and market ups and downs are not included.

Help

Frequently asked questions

Straight answers to common questions about this calculator.

How much can monthly investing grow?

Regular monthly investing adds up over time because you earn on past gains too. The longer you invest and the higher the return, the bigger the total — but returns are not guaranteed.

What is investing the same amount every month?

You put in a fixed amount on a schedule (often monthly). It builds a habit and spreads buys over time instead of guessing the best day to invest.

What is a yearly step-up?

You increase your monthly contribution each year — for example 5% more per year. That can match pay raises and grow your balance faster.

How does inflation affect results?

Inflation means future dollars buy less. Showing results in today's dollars helps you see whether you're on track for a real lifestyle goal.

Your full retirement picture

Retirement is more than money

Free to startNo credit card required

A good retirement plan covers money, health, how you spend your time, people you care about, and what you pass on. That is how Retirelens looks at the full picture.

Finance

Know where you stand and what to do next with your money.

74% of planners reported satisfaction with retirement income vs. 43% of non-planners (Goldman Sachs)

Health

Secure solid coverage, stay ahead with preventive care and healthy habits a staple.

68% of adults ages 50–64 said they were concerned that federal policy changes could affect their health insurance coverage. (University of Michigan)

Purpose

Shape days you look forward to, with steps to get there.

Research shows that a stronger sense of purpose is associated with lower mortality risk among adults over age 50. (American Medical Association)

Connections

Strengthen relationships and build a support circle.

A longitudinal study of adults aged 65+ found that older adults with more diverse social networks had a lower risk of death and better cognitive and physical function than those with less diverse networks. (Chico Health Aging Project)

Legacy

Organize your assets and document so your family isn't left guessing.

Without a proper estate plan, more than half of families experience disputes or have assets end up under court control. (LegalShield)