Retirement Contribution Optimizer
Calculate how much to contribute to your 401(k), IRA, and other retirement accounts each year. Use it when optimizing savings to capture your full employer match and stay within IRS limits.
About this calculator
Retirement savings optimization balances three forces: your disposable income, IRS annual contribution limits, and free money from employer matching. The calculator first determines your maximum feasible contribution: min(availableForRetirement × 12, grossIncome × 0.15). This caps your contribution at either what you can actually afford monthly (annualized) or 15% of gross income — a widely recommended savings target. On top of that, employer match adds grossIncome × employerMatch% directly, representing an instant 100% return on matched dollars. Your current tax bracket matters because pre-tax 401(k) contributions reduce taxable income immediately, while Roth IRA contributions are made after tax but grow tax-free. Years to retirement informs how aggressively you should prioritize tax-deferred versus Roth vehicles. Together these inputs produce a recommended annual contribution figure that captures every dollar of employer match before allocating additional savings.
How to use
Suppose your annual gross income is $80,000, you can set aside $800/month for retirement, your employer matches 4%, and you have 25 years until retirement. Step 1 — annualize available savings: $800 × 12 = $9,600. Step 2 — compute 15% of income: $80,000 × 0.15 = $12,000. Step 3 — take the minimum: min($9,600, $12,000) = $9,600. Step 4 — add employer match: $80,000 × 0.04 = $3,200. Step 5 — total recommended annual retirement contribution: $9,600 + $3,200 = $12,800 per year.
Frequently asked questions
How much should I contribute to my 401k to get the full employer match?
You need to contribute at least as much as your employer's match threshold — typically 3–6% of your gross salary. For example, if your employer matches 100% of contributions up to 4% of a $80,000 salary, contributing at least $3,200 per year captures the full $3,200 match. Failing to reach this threshold means leaving guaranteed compensation on the table. Always prioritize hitting the match ceiling before directing money elsewhere.
What is the difference between contributing to a 401k versus a Roth IRA for retirement savings?
A traditional 401(k) reduces your taxable income today, so you pay taxes when you withdraw in retirement — beneficial if you expect to be in a lower tax bracket later. A Roth IRA uses after-tax dollars, so qualified withdrawals in retirement are completely tax-free — better if you expect higher taxes in the future. The 2024 IRS limit is $23,000 for 401(k) plans and $7,000 for IRAs. Many advisors recommend contributing enough to your 401(k) to capture the full employer match first, then funding a Roth IRA, then returning to the 401(k) for additional contributions.
Why is 15% of gross income the recommended retirement savings rate?
The 15% guideline comes from research by institutions like Fidelity and Vanguard, which found that saving 15% of pre-tax income starting in your mid-20s — including any employer match — typically replaces roughly 45% of pre-retirement income through portfolio withdrawals. Combined with Social Security, this approaches an 80% income-replacement ratio that most retirees need. Starting later than your mid-20s may require saving a higher percentage to compensate for fewer compounding years. The 15% figure is a heuristic, not a guarantee, and should be adjusted based on your expected retirement age and lifestyle goals.