🧾 403(b) / 401(k) Projection Calculator
Project your employer-sponsored retirement account balance using current balance, employee contributions, employer match, expected returns, and contribution growth rate. Includes year-by-year breakdown and CSV download.
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403(b) and 401(k) projection — maximize employer match and compound growth
Employer-sponsored retirement plans like 401(k) and 403(b) are the backbone of retirement savings for many workers. They combine tax-advantaged contributions with the potential for employer matching, and, crucially, long-term compound growth. Projecting future balances helps set contribution targets, evaluate whether you're on track for retirement, and quantify the value of employer match. This page walks through projection mechanics, strategies to maximize match, how contribution growth affects outcomes, and the key caveats when interpreting projections.
How the projection model works
This calculator simulates each year (and sub-periods per contribution frequency) by adding employee contributions, applying employer match up to your employer's cap, and growing the total balance by the assumed investment return. Contributions can increase annually by a contribution growth percentage (to model pay increases or escalating savings). The effect of compound returns — interest on both contributions and previous investment gains — is the primary engine that increases your balance over time.
Employer match: your immediate return on investment
Employer match is effectively free money and often the highest-return single action a plan participant can take. A common match formula might be “50% of contributions up to 6% of your salary.” That means if you contribute 6% of salary, the employer contributes an additional 3% — an immediate 50% boost on your contribution. Always aim to contribute at least enough to capture the full employer match before allocating extra to other investments (unless you have high-interest debt or urgent cash needs).
Contribution frequency and compounding
Contribution timing (monthly vs. biweekly vs. annual) slightly changes the projection because money contributed earlier in the year compounds longer. This calculator assumes even contributions per pay period. For example, biweekly contributions invest slightly earlier on average compared to end-of-month contributions; however, differences are usually modest over long horizons.
Contribution growth (raise-driven increases)
If you increase contributions over time (e.g., 1–3% per year), your projected balance grows faster. Automatic escalation programs that increase your contribution percentage annually are powerful because they pair increased savings with realized income growth — often before lifestyle inflation catches up.
Vesting, fees and taxes — caveats to the projection
Employer contributions may be subject to vesting schedules — unvested match is not guaranteed if you leave employment early. Additionally, plan fees (expense ratios, recordkeeping fees) and taxes (pre-tax contributions taxed at withdrawal; Roth taxed at contribution) are not modeled in this simple projection. Treat the projection as a planning tool — confirm actual balances and fees with your plan provider.
Using the projection to set goals
Combine this projection with retirement goals (desired replacement ratio or target retirement corpus) to determine whether you need to increase savings, shift asset allocation, or consider additional savings vehicles. If the projection falls short, consider increasing contributions, delaying retirement, or supplementing with IRAs and taxable investments.
Practical example
Suppose you have \$50,000 today, contribute \$10,000/year, earn an employer match of 50% up to 6% of salary (\$3,600 on a \$60,000 salary if you contribute at least 6%), expect a 7% annual return, and plan for 25 years. The projection shows how the combination of your ongoing contributions, employer match, and compounding returns can transform modest savings into a substantial retirement nest egg.