IRA Calculator

What Is an IRA Calculator?

An IRA Calculator is an online retirement planning tool that estimates the future value of your Individual Retirement Account (IRA). It calculates how your retirement savings may grow by considering your current balance, annual IRA contributions, expected investment return, current age, planned retirement age, and estimated tax rates.

IRAs are tax-advantaged retirement accounts designed to help individuals save for retirement. Traditional and Roth IRAs differ primarily in how contributions, investment earnings, and withdrawals are taxed.

Unlike a basic retirement calculator, an IRA growth calculator focuses specifically on IRA contributions and tax-deferred investment growth. It helps you understand how consistent investing, compound returns, and time can significantly increase your retirement savings.

Many investors also use a traditional IRA calculator to estimate future account balances, compare different contribution amounts, and understand how tax rates may affect retirement income. Whether you're just opening your first IRA or reviewing an existing retirement plan, an IRA retirement calculator makes long-term financial planning simpler and more informed.

If you're wondering how much your IRA could be worth at retirement or whether increasing your yearly contributions will make a difference, this calculator provides instant estimates without requiring complicated financial calculations.

How to Use the IRA Retirement Calculator

1. Current balance: What's in the IRA today. Zero is fine if you're opening one.

2. Annual IRA contribution: Enter this as a pre-tax amount. The calculator converts it to after-tax dollars for the Roth and taxable columns. The 2026 IRS limit is $7,500, or $8,600 if you're 50 or older.

3. Expected rate of return: Annual, before inflation. The S&P 500 has averaged about 10% nominal over the long run; a 60/40 stock-bond mix closer to 7%. If you want a result in today's purchasing power, knock 2–3 points off for inflation.

4. Current age and retirement age: The gap between them is the number of compounding years, and it's the input with the most leverage on the result. Not that I'd know from experience or anything.

5. Current marginal tax rate: Your top federal bracket, plus state if you pay one. Not your effective rate. For 2026, the federal brackets run 10, 12, 22, 24, 32, 35 and 37%.

6. Expected tax rate in retirement: A guess, and the most consequential one on the page. Most retirees drop a bracket or two because they've stopped earning a salary. Some don't, especially if they have a pension, rental income, or large RMDs.

7. Calculate: Then click "View Annual Schedule" to see the year-by-year balances behind the chart.

How Is the IRA Calculated?

This IRA investment calculator uses the future-value formula for a lump sum plus an annuity: FV = P(1+r)ᵗ + C × [(1+r)ᵗ − 1] / r, where P is your current balance, C is the annual contribution, r is the return, and t is the years to retirement. Traditional after-tax value multiplies that by (1 − retirement tax rate); Roth uses after-tax contributions; taxable uses an after-tax return.

The core formula

$FV = P(1+r)^t + C \times \frac{(1+r)^t-1}{r}$

• P = current IRA balance

• C = annual contribution (made at the end of each year)

• r = expected annual return, as a decimal

• t = retirement age − current age

The first term is your existing balance compounding. The second is the contributions, each one compounding for however many years remain after it goes in. That's an ordinary annuity. If you contribute on January 2 instead of December 31 you'd multiply the second term by (1+r) and get slightly more, but the difference is small next to the uncertainty in r.

Three accounts, three tweaks

Traditional IRA (after tax): FV × (1 − T_retire), where T_retire is your expected retirement tax rate. This assumes every withdrawal is taxed at that flat rate, which is a simplification. In practice, withdrawals are taxed as ordinary income, so your first dollars out fall into low brackets and the rest into higher ones.

Roth IRA (after tax): You fund a Roth with money that's already been taxed, so the calculator shrinks both P and C by your current rate: P × (1 − T_now) and C × (1 − T_now). Then it grows at the full return, and nothing comes off at the end. Algebraically, Roth after tax = Traditional before tax × (1 − T_now). That's why, if T_now equals T_retire, the two after-tax results are identical in dollars. The Traditional/Roth question is entirely a bet on which rate is higher.

Taxable account (after tax): Same after-tax starting amounts as the Roth, but the return is haircut every year: r × (1 − T_now). The model assumes all gains are taxed annually at your marginal rate, which is harsher than reality for a buy-and-hold index fund (long-term capital gains rates are 0, 15 or 20%, and unrealised gains aren't taxed at all). Treat the taxable figure as a floor.

Worked example

Age 30, retiring at 65. $20,000 in the account, $7,000 a year, 6% return, 25% tax now, 15% in retirement.

• t = 35 years; 1.06³⁵ = 7.686

• Balance term: 20,000 × 7.686 = $153,722

• Contribution term: 7,000 × (7.686 − 1) / 0.06 = $780,043

• Traditional before tax: $933,765

• Traditional after tax: 933,765 × 0.85 = $793,700

• Roth after tax: 933,765 × 0.75 = $700,324

• Taxable after tax: 15,000 × 1.045³⁵ + 5,250 × (1.045³⁵ − 1) / 0.045 = $497,867

Those are the numbers you'll see if you hit Calculate without touching anything. The Traditional edge here is $93,377, and every cent of it comes from the 10-point drop in tax rate. Not from the account being better. From the timing of the tax.

Traditional IRA vs Roth IRA: Which Should You Pick?

Pay tax now (Roth) if you expect a higher rate in retirement. Pay tax later (Traditional) if you expect a lower one. Equal rates, equal outcome.

That's the math answer. The practical answer has a few wrinkles the formula doesn't see.

You might not be allowed to deduct a Traditional contribution. If you (or your spouse) have a workplace retirement plan, the deduction phases out. For 2026: single filers lose it between $81,000 and $91,000 of modified AGI; married filing jointly between $129,000 and $149,000 if the contributing spouse is covered, or $242,000 to $252,000 if only the other spouse is. Above those, a Traditional contribution is non-deductible and the calculator's Traditional column overstates your result.

You might not be allowed to contribute to a Roth at all. Roth eligibility phases out in 2026 from $153,000 to $168,000 single and $242,000 to $252,000 married filing jointly; IRS Publication 590-A has the full tables by filing status. High earners get around this with a backdoor Roth, which is beyond what this calculator models.

Roths have no required minimum distributions. Traditional IRAs force you to start withdrawing at 73 (75 if you were born in 1960 or later). Those forced withdrawals are taxable income, and for people with large balances they can push the retirement tax rate up, not down. Run the RMD calculator on your projected Traditional balance before assuming a low retirement bracket.

Roth contributions can come back out penalty-free. Not the earnings, but the money you put in. That flexibility has value the formula doesn't price.

The $7,500 is one limit across all your IRAs combined. You can't put $7,500 in each.

If you want to look at the Roth side in isolation, the Roth IRA calculator breaks it out on its own.

Three Scenarios Through the IRA Growth Calculator

Same tool, three lives. Traditional after-tax first, then Roth, then taxable.

Starting at 25 with almost nothing. $10,000 balance, $7,000 a year, 7%, 22% now, 12% in retirement, retire at 65. Forty years. Traditional after tax $1.36M, Roth $1.21M, taxable $804k. The pre-tax balance is $1.55M and the contributions total $280,000. Everything else is compounding.

Mid-career, 40, decent start. $75,000 balance, $7,000 a year, 6%, 24% now and 22% in retirement. Twenty-five years. Traditional after tax $551k, Roth $537k, taxable $413k. With only two points between the tax rates, Traditional and Roth are nearly a wash. This is the person who should think hardest about RMDs and flexibility rather than the after-tax gap.

Catching up at 50. $150,000 balance, the full $8,600 catch-up contribution, 5.5%, 32% now, 24% in retirement, retiring at 65. Traditional after tax $401k, Roth $359k, taxable $292k. Fifteen years isn't long, but the 8-point rate drop makes Traditional clearly better here. Someone in the 32% bracket today who expects 24% later is the textbook Traditional case.

Notice the pattern: the bigger the gap between your current and retirement rate, the bigger the Traditional advantage. When the gap is small, the tiebreakers (RMDs, Roth flexibility, whether you can even deduct) decide it.

What Rate of Return Should You Use?

This is the input where an IRA investment calculator is only as good as your guess. Six or seven percent nominal is defensible for a diversified stock-heavy portfolio held for decades. Ten is what the S&P 500 has historically delivered, but your portfolio probably isn't 100% S&P 500 all the way to 65, and the fees on whatever you hold come out of that.

If you'd rather see the result in today's dollars, use a real return: nominal minus inflation. Four to five percent real is the range most planners use. The 25-year-old's $1.36M after tax at 7% nominal becomes about $710k at 4.5% real. Same portfolio, same contributions, far less exciting, far more honest about what it buys.

Whatever you pick, run the IRA retirement calculator twice more at two points lower and two points higher. If the plan only works at the high end, it doesn't work.

Mistakes the Calculator Can't Catch

• Entering your effective tax rate instead of your marginal rate. Traditional contributions save tax at the margin. A 24%-bracket household with a 15% effective rate should enter 24.

• Assuming a low retirement rate without checking RMDs. A $1.5M Traditional balance forces a first-year RMD of roughly $56,000 at 73. Add Social Security and you may be right back in the 22% bracket.

• Contributing more than the limit. The IRA retirement calculator will happily accept $15,000 a year. The IRS won't (unless you're using it as a SIMPLE IRA calculator, where $17,000 is legal). Excess contributions carry a 6% excise tax every year until removed.

• Forgetting state tax. The calculator's tax rates are whatever you type. If you live in California now and plan to retire in Florida, your effective rate drop is bigger than the federal brackets alone suggest, and that favours Traditional.

• Using the taxable column as a fair comparison. It's deliberately pessimistic. A low-turnover index fund in a taxable account does better than the model shows.