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.
Last updated: September 2026
Formula below · 2 sources (CFPB, Wikipedia) · Updated Sep 2026
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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 contribution: min(availableForRetirement × 12, grossIncome × 0.15, $32,000). This caps it at what you can afford (annualized), at 15% of gross income — a widely recommended savings target — and at the 2026 IRS limits for a worker under 50 using both a 401(k) ($24,500) and an IRA ($7,500). On top of that, the employer match adds grossIncome × employerMatch%, but never more than you contribute yourself (it assumes a dollar-for-dollar match up to that percentage of pay). The match is an instant 100% return on matched dollars, so the result is the total going into your accounts each year. Pre-tax 401(k) contributions reduce taxable income now, while Roth contributions are made after tax but grow tax-free — the split is up to you.
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 2026 IRS limit is $24,500 for 401(k) plans and $7,500 for IRAs (plus catch-up contributions from age 50). 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.