Traditional IRA Calculator

Inside the account, the math is the same compound interest math used everywhere else on this site. Each month the balance grows by the monthly rate, new contributions are added, and the next month growth applies to the larger total. The difference is what does not happen. In a taxable account, interest, dividends, and realized gains can create a tax bill each year, which quietly lowers the amount left to compound. Inside a traditional IRA, that yearly bill is deferred. The full pre-tax balance stays invested and keeps compounding until withdrawal. Over decades, avoiding that annual drag can add a meaningful amount to the pre-tax balance, even at the same investment return.

Deferral is not the same as forgiveness. The tax is collected when money leaves the account, and it applies to the whole withdrawal amount that has not been taxed before. That includes growth, which was never taxed along the way. For planning, treat the projected balance as a gross figure. If you want a rough spendable figure, apply the tax rate you expect in retirement to the withdrawal. Your actual rate will depend on your total income in that future year, other income sources, and the tax rules then in place. This is also where required minimum distributions enter the picture. Once you reach the required starting age in your early 70s, with the exact age depending on birth year, the rules require minimum withdrawals each year. Those withdrawals add to taxable income whether you need the cash or not, so the size of the pre-tax balance late in retirement affects your tax picture year by year.

Both accounts shelter growth while the money stays inside. The difference is when tax is paid. With a traditional IRA, a qualifying contribution can lower taxable income now and withdrawals are taxed later. With a Roth IRA, contributions are made with after-tax money, so there is no deduction now, and qualified withdrawals in retirement come out tax-free. If you project the same contributions at the same return, the pre-tax balances look identical. The spendable results differ because the traditional balance still owes tax and the Roth balance does not. Any honest comparison must put both results on an after-tax footing. Compare the traditional balance after an estimated withdrawal tax with the Roth balance as shown.

Roth tends to win when your current tax rate is low compared with the rate you expect in retirement, when you are early in your career and income is likely to rise, when you want tax-free income later to manage your retirement tax bracket, or when you value the flexibility that comes with withdrawals that do not add to taxable income. Traditional tends to win when your current rate is clearly higher than your expected retirement rate, when the deduction now frees cash that lets you contribute more, or when you expect lower income years in early retirement to withdraw or convert at lower rates. Many people end up with both account types across a working life, using traditional contributions in high income years and Roth contributions in lower income years. See the sibling Roth IRA calculator to run the same deposits with tax-free withdrawal framing and compare the two after-tax views side by side.

1. Treating the projected balance as spendable cash. The calculator shows a pre-tax total. Every dollar withdrawn will face income tax at the rates and income levels that apply in that future year. If you plan spending from the gross number, you will overstate retirement income by a wide margin.
2. Assuming every contribution is deductible. Deductibility depends on income and on workplace plan coverage for you and, where relevant, your spouse. A contribution can be allowed while the deduction is reduced or unavailable. Confirm your own treatment each year instead of carrying forward an old assumption.
3. Picking traditional only for the upfront deduction. The deduction feels concrete and the future tax feels abstract, so the choice gets made backward. Work the comparison the other way. Estimate your retirement tax rate first, then decide whether paying tax now at a known rate beats deferring to that future rate.
4. Forgetting required withdrawals in the plan. Minimum required withdrawals in retirement add taxable income on a schedule you do not fully control. A very large pre-tax balance late in life can push income higher than planned. Thinking about account size, withdrawal order, and possible lower income years well before that stage gives you more options.
5. Using one optimistic return and stopping there. A single high rate hides the range of outcomes. Run a cautious rate with the same contributions. If the plan only works at the optimistic rate, increase the contribution or lengthen the horizon rather than raising the rate in the box until the answer looks pleasant.
6. Leaving deposits as uninvested cash. Contributions moved into the IRA but left in cash do not earn the return entered in the calculator. The projection assumes contributions are invested on schedule. Keep the transfer and the investment step together so the account matches the model.

Start with the tax rate question, because it decides more than the return assumption does. Write down the marginal rate a deduction would save you this year, as best you can tell from your income and workplace plan status. Then write down the rate you realistically expect on retirement withdrawals, given other income such as pensions, benefits, and part time work. If the first number is clearly higher, a traditional IRA deserves a close look. If the second number looks higher, or you are early in your career with room for income to grow, run the Roth comparison on the sibling page before you commit the year contribution. When the two rates look similar, flexibility often breaks the tie, and holding some money in each type gives you choices later that a single account type cannot.

Next, set the contribution from cash flow and keep it boring. A monthly amount you can sustain through a full year, including expensive months, will compound longer than a larger amount that gets skipped and restarted. Keep an emergency fund outside the IRA so a surprise bill does not force an early withdrawal, which can bring tax and penalties into a plan built for decades. Review the choice once a year when income or job coverage changes, because a change in workplace plan status or earnings can flip whether a deduction is available and whether it is worth taking. The calculator handles the growth math. Your job is the tax timing, the steady deposit, and the discipline to leave the account alone until retirement.