A Roth IRA calculator projects the tax-free balance you can build by retirement from a starting amount, an annual contribution, an expected return, and the years remaining until you retire. This calculator estimates Roth IRA accumulation using the future-value-of-annuity formula, expressed as a projected tax-free balance plus a 4%-rule monthly withdrawal. Qualified withdrawals after age 59½ and a 5-year holding period are free of federal income tax on both contributions and earnings.
The 2026 IRS contribution limit is $7,000 for savers under 50 and $8,000 with the 50-plus catch-up (per the IRS, 2025). Eligibility phases out between $146,000 and $161,000 of modified adjusted gross income for single filers, and between $230,000 and $240,000 for joint filers; above the upper bound, a backdoor Roth conversion is the typical workaround.
The Roth advantage compounds with time. A $7,000 annual contribution over 40 years at a 7 percent real return becomes roughly $1.4 million, and qualified withdrawals leave that balance entirely outside federal income tax. The same growth in a taxable brokerage account would surrender 15 to 20 percent to long-term capital gains. Roth typically wins when your retirement bracket equals or exceeds your bracket today, which describes most savers in their first two decades of work; pair this projection with a tax-bracket forecast, never substitute it.
Key takeaway
The Roth IRA's superpower isn't the tax shelter, it's that decades of growth come out tax-free. A $7,000 annual contribution over 40 years at 7% becomes ~$1.4M, and you keep all of it. The same projection in a taxable account would lose 15–20% to long-term capital gains. That's the real Roth advantage: not the contribution-side savings, but compounding on after-tax money once and never paying tax on the growth again.
How it's calculated
The projection uses the future-value-of-annuity formula:
FV = P × (1 + r)^t + C × ((1 + r)^t − 1) / r
Where:
- P is your current Roth IRA balance
- C is your annual contribution (assumed constant over the projection)
- r is the expected annual return as a decimal (7% → 0.07)
- t is the years remaining (retirement age − current age)
The first term grows your existing balance over the time horizon; the second term sums the future value of every annual contribution along the way. Contributions are assumed to be made at year-end (ordinary annuity); real-world Roth contributions made earlier in the year grow slightly more.
The 4% rule output applies the Trinity Study's safe withdrawal rate: the historical maximum first-year withdrawal that survived a 30-year retirement under worst-case sequence-of-returns scenarios is roughly 4% of the starting balance, adjusted for inflation thereafter.
Source: Future-value-of-annuity formula, FV = P(1+r)^t + C × ((1+r)^t − 1) / r
Examples
Starting at 30 with $5,000, contributing the max for 35 years
- Current Roth IRA balance $5,000
- Annual contribution $7,000
- Current age 30
- Retirement age 65
- Expected annual return 7%
Starting with $5,000, contributing the 2026 max of $7,000 per year, and earning 7% annually for 35 years grows to roughly $1.02M at age 65. Of that, $250,000 is contributions; the other $771,000 is tax-free growth. Under the 4% rule, that supports about $3,406 per month in retirement income, fully tax-free at the federal level.
Late starter: age 45, $0 balance, 20 years to age 65
- Current Roth IRA balance $0
- Annual contribution $8,000
- Current age 45
- Retirement age 65
- Expected annual return 7%
Starting at 45 with the catch-up-eligible $8,000 annual contribution for 20 years yields about $328,000 at 65, meaningful but visibly less than the early-starter scenario despite higher contributions. Time matters more than rate; the same 7% return over 35 years instead of 20 produces ~3× the final balance with less total money in.
Frequently asked questions
What's the contribution limit for a Roth IRA in 2026?
For 2026, the IRS contribution limit is $7,000 if you're under 50 and $8,000 if you're 50 or older (the extra $1,000 is the catch-up contribution). These limits change occasionally for inflation, always verify the current year's number on the IRS website before contributing. Income phase-outs further reduce or eliminate eligibility above certain modified-adjusted-gross-income thresholds.
When can I withdraw from a Roth IRA without penalty?
Contributions can be withdrawn anytime, tax- and penalty-free, because you already paid tax on that money. Earnings require both (a) reaching age 59½ and (b) the account being open at least 5 years ("5-year rule") to be withdrawn tax-free. Earnings withdrawn before meeting both conditions are typically subject to ordinary income tax plus a 10% penalty, with limited exceptions (first-time home purchase up to $10K, qualified education expenses, disability, etc.).
What rate of return should I use in this calculator?
For long-horizon projections, 6–7% real (after-inflation) return is a reasonable conservative estimate based on multi-decade historical US balanced-portfolio returns (around 7% real, 10% nominal for 100% equities). If you're modeling nominal dollars (today's prices, ignoring inflation), use the higher number. If you're modeling inflation-adjusted dollars (purchasing power), use the lower one. Historical returns aren't guaranteed, especially over shorter horizons, this calculator shows deterministic growth, not a probability distribution.
Should I contribute to a Roth IRA or a traditional IRA?
Rule of thumb: Roth wins if your retirement tax rate is the same as or higher than your current tax rate. Most people early in their career are below their eventual peak earnings (and thus their peak tax bracket), so Roth typically wins for them. People in their peak earning years often find traditional IRA contributions more tax-efficient because the up-front deduction comes out at a higher rate than the eventual withdrawal. The honest answer involves running both projections; this calculator handles the Roth side.