Roth IRA Calculator: Project Tax-Free Retirement Growth
Project how a Roth IRA could grow when funded with after-tax dollars, where qualified withdrawals in retirement come out completely tax-free.
Adjust the inputs and select Calculate for a full breakdown.
Year-by-year growth schedule
Compare Common Scenarios
How the numbers shift across typical situations for this calculator:
| Scenario | Future value | Total contributions | Total interest earned |
|---|---|---|---|
| $8k · $500/mo · 8% · 30yr | $832,665.56 | $188,000.00 | $644,665.56 |
| $0 · $583/mo · 7% · 35yr | $1,050,014.83 | $244,860.00 | $805,154.83 |
| $25k · $500/mo · 9% · 20yr | $484,172.22 | $145,000.00 | $339,172.22 |
| $50k · $250/mo · 6% · 15yr | $195,409.36 | $95,000.00 | $100,409.36 |
How This Calculator Works
Enter your current Roth IRA balance, the average annual return you expect, the years until retirement, and your monthly contribution. The calculator compounds the account monthly and adds each contribution. Because Roth contributions are already taxed, the projected balance is money you can later withdraw tax-free once the account qualifies.
The Formula
Future Value with Regular Contributions
P = starting amount, PMT = monthly contribution, r = monthly rate (annual ÷ 12), n = number of months
Worked Example
Starting with $8,000 and adding $500 a month at an 8% average return for 30 years produces a balance near $832,700. You contributed $188,000 of already-taxed income, so the remaining $644,700 of growth is never taxed provided the withdrawals are qualified.
Key Insight
The Roth advantage is the tax treatment of growth, not the growth itself. Every dollar of compounding shown here escapes tax in retirement, which makes a Roth most valuable when you expect your future tax rate to match or exceed today's.
Frequently Asked Questions
How is a Roth IRA taxed?
You contribute money that has already been taxed, so contributions and all investment growth can be withdrawn tax-free once the account is at least five years old and you are 59½ or older.
Is there a contribution limit?
Yes. The IRS sets an annual Roth IRA contribution limit, with a higher cap for savers age 50 and over. Keep your monthly contribution within one-twelfth of whichever limit applies to you.
Can high earners contribute to a Roth IRA?
Direct contributions phase out above an income threshold set by the IRS. Some savers above the limit use a backdoor Roth conversion instead; those rules are intricate, so professional advice helps.
Roth or traditional IRA — which is better?
A Roth wins if your tax rate in retirement is the same or higher than today. A traditional IRA can win if you expect a lower rate later, since it defers tax instead of prepaying it.
Can I withdraw my contributions early?
Your own contributions can be withdrawn at any time without tax or penalty because they were already taxed. Withdrawing the growth early, however, can trigger income tax and an additional penalty.
Related Calculators
Data Sources & Benchmarks
This calculator draws on 3 independent, dated sources. The starting values for expected annual return are taken from the benchmarks below and refresh whenever the snapshots are updated.
Methodology & Review
The projection compounds the account monthly at a constant expected return and a fixed monthly contribution. It assumes contributions stay within annual IRS limits and that withdrawals are qualified; it excludes investment fees.
Written by Ugo Candido · Last updated May 17, 2026.