The Future Value Formula
This calculator projects growth using compound interest applied monthly, combining both your existing balance and ongoing contributions:
Future Value = Current Balance × (1 + r)ⁿ + Monthly Contribution × [((1 + r)ⁿ − 1) ÷ r]
Where r is the monthly return rate (annual rate ÷ 12) and n is the total number of months.
Why Roth IRA Growth Is Especially Valuable
Unlike a traditional 401k or IRA, qualified withdrawals from a Roth IRA in retirement are completely tax-free — meaning the entire projected growth shown here, not just your contributions, comes out tax-free if you follow the withdrawal rules (generally, account open 5+ years and age 59½+).
2024 Contribution Limits
For reference, the IRS Roth IRA contribution limit for 2024 was $7,000 (or $8,000 for those 50+), subject to income eligibility limits — check current IRS guidance, as both limits are adjusted periodically.
Why Starting Early Matters So Much
Because returns compound on both your contributions and your prior growth, money invested earlier has dramatically more time to compound. Two savers contributing the same monthly amount, but starting 10 years apart, can end up with a significantly different final balance — the earlier starter often ends up with a much larger sum despite contributing the same total amount over their overlapping years.
Important Caveat
This projection assumes a constant annual return, which real investments never provide exactly — actual markets fluctuate year to year. Use a conservative estimated return (historically, diversified stock market returns have averaged around 7-10% annually before inflation over long periods, though individual results vary) and treat this as a planning estimate, not a guarantee.