Investing

Compound Interest Calculator

Project investment growth with flexible compounding, contribution schedules, inflation toggles, and AI savings insights.

Plan your growth

Adjust principal, contributions, and compounding to see how your portfolio evolves.

Scenario comparison

Copy your base plan, tweak rate or deposits, and measure the difference.

Projection summary

Future value

$71,771.62

Total contributions

$39,419.00

Total growth

$22,352.63

Inflation-adjusted value

$57,735.62

At 6% for 10 years, compounding magnifies contributions—experiment with deposits or returns to accelerate growth.

Yearly milestones

Latest checkpoints highlight cumulative deposits, growth, and real value.

Showing last 8 years
Y3/10Contributions: $11,017.44
Nominal balance$24,055.87
Real balance (inflation-adjusted)$22,535.56
Y4/10Contributions: $14,837.79
Nominal balance$29,486.40
Real balance (inflation-adjusted)$27,028.26
Y5/10Contributions: $18,734.54
Nominal balance$35,330.80
Real balance (inflation-adjusted)$31,688.31
Y6/10Contributions: $22,709.24
Nominal balance$41,616.20
Real balance (inflation-adjusted)$36,522.21
Y7/10Contributions: $26,763.42
Nominal balance$48,371.38
Real balance (inflation-adjusted)$41,536.72
Y8/10Contributions: $30,898.69
Nominal balance$55,626.98
Real balance (inflation-adjusted)$46,738.89
Y9/10Contributions: $35,116.66
Nominal balance$63,415.54
Real balance (inflation-adjusted)$52,135.99
Y10/10Contributions: $39,419.00
Nominal balance$71,771.62
Real balance (inflation-adjusted)$57,735.62

How do monthly deposits affect the outcome?Every recurring deposit compounds alongside the principal, so even small monthly contributions produce significant growth over time.

Can I include inflation in the projection?Enable inflation to see real purchasing power—vital when planning decades ahead.

How often should I revisit the plan?Review annually or after major life events to adjust contributions, risk tolerance, or goals.

How to model compound growth

Project savings or investment balances in a few inputs.

  1. Set your starting point

    Enter the initial balance, annual interest rate, and number of years.

  2. Choose compounding and contributions

    Select how often interest compounds and add recurring deposits if you plan to contribute.

  3. Adjust for inflation

    Toggle the inflation slider to see real (purchasing power) results alongside nominal growth.

  4. Review the summary

    Check ending balance, total interest, contribution totals, and the growth chart.

Case study: Retirement catch-up plan

Jordan wants to grow a mid-career retirement account with consistent monthly deposits.

Starting balance
$5,000
Monthly contribution
$150
Target horizon
20 years at 6% APY
  1. Baseline projection

    Jordan enters the current balance, 6% rate, monthly compounding, and 20-year horizon to view nominal growth.

  2. Real return view

    They enable a 2% inflation adjustment to understand the purchasing power of the future balance.

  3. Savings boost

    By increasing deposits to $200 per month, the summary shows an extra $13,000 in ending balance.

Planning insight

Jordan commits to the higher contribution knowing the inflation-adjusted balance still meets retirement goals.

Compound interest FAQs

Does the calculator handle daily compounding?

Yes. Pick any frequency from annual to daily; the effective annual rate updates automatically.

Can I delay contributions?

Use the contribution start delay to skip deposits until the year or month you choose.

How does inflation adjustment work?

Real balance divides the nominal result by cumulative inflation so you can compare future purchasing power to today's dollars.

Further reading

  • Bogleheads investing philosophy
  • Compound interest explained
  • Federal Reserve economic data

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