401k Calculator

401k Calculator is a website that provides free online tools for projecting 401(k) retirement plan outcomes. Users can input details such as current age, salary, existing balance, contribution rate, employer match, and expected return to see a live projection of their retirement balance. The site also offers focused calculators covering employer match, early-withdrawal penalties, Roth versus traditional contributions, paycheck impact, and required minimum distributions.

The main calculator compounds your contributions, your employer's match, and your existing balance at an expected annual return until retirement. It shows the split between what you contributed and what growth added, updating live as you type. For example, saving $500 a month for 30 years at a 7% return grows to roughly $567,000, of which about $387,000 is investment growth rather than money you put in.

The tool uses the IRS figures for the 2026 tax year, including a $24,500 elective-deferral limit and an $8,000 age-50 catch-up. It also accounts for a $11,250 limit at ages 60–63 and a $72,000 combined §415(c) limit. These figures are updated regularly to reflect current IRS rules.

Beyond the main projection tool, the site offers a 401k Match Calculator, a Withdrawal Penalty Calculator, a Roth vs Traditional 401k Calculator, a Paycheck Calculator, and a How Long Will My 401k Last Calculator. There are also specialized tools for Individual 401k contributions, RMDs, growth, and divorce scenarios.

The match calculator uses the formula: Match = Salary × min(Your %, Cap %) × Rate. It shows exactly how much free money an employer adds to a 401k and the contribution rate needed to capture every dollar of the match. This helps users understand the value of their employer's contribution.

The site models investment returns as a steady average, noting that real markets are volatile. It warns that the order of returns (sequence risk) affects outcomes, especially in retirement. The projections are shown in pre-tax nominal dollars, meaning inflation reduces real purchasing power over time.

The withdrawal penalty calculator calculates the net amount after applying ordinary income tax plus the 10% §72(t) additional tax before age 59½. It helps users understand the financial impact of accessing their funds early.

The RMD calculator divides the prior-year-end balance by the IRS Uniform Lifetime Table factor. This ensures users know the minimum amount they must withdraw annually from their retirement accounts to avoid penalties.

This calculator uses the formula Bₙ = Bₙ₋₁(1 + r/12) − Wₙ to project when a balance will run out. It factors in monthly returns less inflation-adjusted withdrawals, helping users estimate their retirement duration.

The Roth vs traditional calculator compares the after-tax retirement value of Roth and traditional 401k contributions side by side. It uses the formula Roth = C·F vs Trad = C·F(1 − Tr) + (C·Tc)·F to show which option leaves more money after taxes.

The key inputs include current age, annual salary, current 401k balance, contribution rate, employer match rate, match limit, expected annual return, and annual salary growth. Users can adjust these figures to see how small changes impact the final retirement balance.

The tool incorporates specific catch-up limits, such as an $8,000 age-50 catch-up and a $11,250 limit for ages 60–63. These figures are applied alongside the standard elective-deferral limit to provide accurate projections for older employees.

While not explicitly detailed in the main text, user discussions highlight that Solo 401(k) calculators allow self-employed individuals to save nearly double compared to a SEP IRA at the same income level. This feature is crucial for independent contractors and business owners.

The site publishes every formula and assumption used, allowing users to check the numbers rather than just trust them. It operates with no account system, no lead capture, and no paid product placements, focusing entirely on the arithmetic.

The official website of 401k Calculator is 401kcalculator.info.