Roth IRA Calculator Guide
The Roth vs. Traditional IRA decision comes down to a single question: would you rather pay income tax on this money now, while you're contributing, or later, when you withdraw it in retirement? Everything else follows from that one choice.
The Core Tax Tradeoff
Traditional IRA contributions are typically made pre-tax (or are tax-deductible), reducing your taxable income today, but withdrawals in retirement are taxed as ordinary income. Roth IRA contributions are made with after-tax money — no upfront deduction — but qualified withdrawals in retirement, including all the growth, are completely tax-free. The Roth IRA calculator's side-by-side comparison against a Traditional IRA is really a bet on whether your tax rate will be higher or lower in retirement than it is today.
Why Time Horizon Favors Roth for Younger Savers
Because Roth growth is never taxed, the earlier your money starts compounding in a Roth account, the more total tax-free growth you eventually get to keep. Younger savers are also often in a lower tax bracket now than they expect to be later in their careers, making the "pay tax now, at a low rate" trade especially favorable. Someone decades from retirement typically has more to gain from a Roth than someone a few years out, where the tax-rate bet matters less because there's less time for growth to compound tax-free.
Contribution Limits and Income Caps
Roth IRAs have both an annual contribution limit (adjusted periodically for inflation, plus a catch-up amount for those 50+) and an income eligibility cap — high earners may be phased out of contributing directly at all. These figures change over time, so always confirm the current limits and thresholds rather than relying on a number you saw in a prior year, and consider a backdoor Roth conversion strategy if you're above the income cap and still want Roth exposure.