Enter your age, contributions, and expected returns to project both account types side by side, including the tax trade-off each one makes.
Over 35 years, total contributions made: $0
A Traditional IRA is funded with pre-tax dollars — you may get a tax deduction the year you contribute — and grows tax-deferred until retirement, at which point withdrawals are taxed as ordinary income. A Roth IRA flips that: you contribute after-tax dollars today, get no deduction, but qualified withdrawals in retirement — including every dollar of growth — come out completely tax-free. Both share the same core mechanics otherwise: money invested grows tax-free while it sits inside the account, and both have the same combined annual contribution limit.
The rule of thumb: a Roth IRA tends to come out ahead if you expect to be in a higher tax bracket in retirement than you are right now, because you're locking in today's lower rate on every dollar contributed. A Traditional IRA tends to come out ahead if you expect a lower bracket in retirement, since you defer tax now and pay it later at a cheaper rate. The two readouts above make this trade-off concrete with your actual numbers rather than leaving it as an abstract rule — compare the "after-tax value" row for each account directly.
The IRS sets an annual dollar limit on how much you can contribute across all your IRAs combined, plus a higher "catch-up" limit once you turn 50. These limits are periodically adjusted and change from year to year, so this calculator deliberately doesn't hardcode a specific number that would go stale — check irs.gov for the current year's limit before deciding how much to contribute.
Yes — you can split contributions across both a Traditional and a Roth IRA in the same year, but the combined total across every IRA you own still can't exceed the single annual IRA limit set by the IRS. Roth contributions also phase out entirely above certain income levels, which doesn't limit Traditional IRA contributions themselves (though the tax deduction can phase out if you or a spouse are covered by a workplace retirement plan).
An IRA is opened on your own through a brokerage, entirely independent of any employer, which means there's no employer match and the annual contribution limit is generally lower than a 401(k)'s. A 401(k) is employer-sponsored and often comes with a matching contribution — effectively free money that's usually worth capturing before maxing out an IRA. See the 401(k) Calculator, a companion tool, to model that employer-sponsored side of retirement saving on its own.
Worked example: starting at age 30 with a $10,000 balance, contributing $7,000/year until retirement at 65 (35 years) at a 7% annual return, the balance grows to about $1,142,160. Total contributions over those 35 years: $245,000. As a Traditional IRA taxed at 15% on withdrawal, that leaves an after-tax value of about $970,836 (roughly $171,324 paid in tax at withdrawal). As a Roth IRA, the same $245,000 of contributions would have cost about $53,900 in tax today at a 22% marginal rate, but the full $1,142,160 balance comes out tax-free in retirement. In this example the Roth's after-tax value comes out higher — not because 22% beats 15%, but because that 22% is applied only to the $245,000 of contributions, while the Traditional IRA's 15% withdrawal tax is applied to the entire $1,142,160 grown balance, a much larger base. This is exactly the trade-off worth checking with your own numbers: a lower expected retirement tax rate helps the Traditional side, but it's taxing a bigger pile of money, so it doesn't automatically win.