Free calculator
401(k) calculator
Model a U.S. workplace 401(k)–style balance using salary, an employee deferral %, optional employer match (rate on deferrals capped by % of salary), optional annual salary growth, a nominal expected return, and compounding. Project a balance at retirement or set a goal and read the deferral % that reaches it under the same assumptions. Optional inflation shows one “today’s dollars” line—illustration only. Copy FV patterns into Google Sheets or Excel when you move the story into a file.
When to use this calculator
A transparent illustration when the story is “% of salary + match” rather than a fixed dollar monthly—before you build a fuller spreadsheet.
- Ballpark how deferral %, match, and return assumptions might compound to a retirement date.
- Ask “what deferral % gets me near $X?” under fixed match and return assumptions (not the same as your plan’s official projection).
- Compare a row you will paste into a 401(k) tab in a model after you lock match and growth in one place the team can explain.
- Teach end-of-month contributions with employer match next to a short methodology—then jump to retirement savings for fixed $/month without salary.
We turn current and retirement ages into a horizon in months (same rounding story as the retirement savings tool). Each month we apply the same monthly growth factor as our compound interest tool from your nominal annual return and compounding pick, then add employee and employer contributions at month-end.
Ages to months
We use retirement age − current age, rounded to whole months like the other planning calculators. Retirement must be after current age.
Salary, deferral, and match (one rule)
Each projection year block starts from a salary (it can grow every 12 months if you set growth > 0). Employee annual deferral = deferral % × salary. Eligible deferral for match = the minimum of that annual deferral and (match cap % × salary). Employer annual match = (match rate % × eligible deferral)—for example 50% on the first 6% of salary is match rate 50, cap 6.
Month-by-month balance
For each month: balance → balance × monthlyGrowth + employeeMonthly + employerMonthly, where monthly amounts are annual ÷ 12 within each 12‑month salary block. This keeps the math auditable when salary steps once per year.
Target mode (deferral %)
We binary-search a deferral % between 0 and 100 so the projected nominal balance meets your goal (when possible). If 100% deferral still falls short, we show that the goal is unreachable under the other assumptions.
Optional inflation deflates only the displayed “today’s dollars” figure by (1 + inflation)^years—a textbook shortcut, not a forecast of living costs or tax brackets.
For fixed dollar monthly saving without salary or match, use the retirement savings calculator. For generic growth without a 401(k) story, use compound interest. For rollover tax timing or FINRA “save the max” YTD checks, use dedicated tools—see the FAQ.
Google Sheets & Excel (FV-style)
This page simulates monthly employee + employer flows. In a sheet you often collapse that to one PMT per month (= employee/12 + employer/12) when both are level for the year, then FV(annualRate/12, months, -totalMonthly, -start, 0) with end timing. Replace names with your cells.
=FV(annualRate/12, months, -totalMonthly, -start, 0)totalMonthly should include both your deferral and employer match when you keep them flat for the horizon. If salary grows in your sheet, rebuild monthly each year instead of one constant PMT.
=SUM(monthly_column)Many real models use a row per month or per year with changing salary and match—mirror this page’s stepping (salary growth every 12 months) or your SPD rules in the sheet.
Frequently asked questions
How do I enter “50% match on the first 6% of salary”?
Set Employer match (% of eligible deferral) to 50 and Match applies to deferral up to (% of salary) to 6. We compute eligible annual deferral as the minimum of your actual annual deferral (deferral % × salary) and 6% × salary, then multiply by 50% for the employer piece.
Why is there no Roth vs traditional toggle?
This page shows nominal account growth with the dollars you defer and the match dollars credited—tax treatment of contributions and withdrawals changes spendable outcomes but not that simple balance path. Use tax software or a planner for RMD, Roth conversion, and bracket questions.
Do you enforce IRS 401(k) contribution limits?
No. Limits, catch-up, and plan rules change and depend on your age and plan text. We may show a soft note when your modeled annual deferral looks very high—not a compliance determination. Check IRS.gov and your administrator for authoritative limits.
Is this the FINRA “Save the Max” or similar YTD tool?
No. Those tools track how much room you have left this calendar year against IRS limits and sometimes plan features. This page is a long-horizon projection with assumptions you type—not a payroll or compliance engine.
Can you model a 401(k) rollover when I change jobs?
Not here. Rollovers mix tax timing, withholding, and destination account rules. Treat this page as “stay invested and keep deferring” math; ask a planner or use an IRA/401(k) rollover calculator from your custodian for that decision.
When should I use the retirement savings calculator instead?
Use retirement savings for a constant dollar monthly contribution without salary or employer match. Use this page when the story is “% of salary + match cap”.
How do I rebuild this in Google Sheets or Excel?
Either build a month row with salary steps and match like the methodology, or—when totals are flat for the whole horizon—use FV(annualRate/12, nMonths, -(employeeMonthly+employerMonthly), -start, 0) with end timing. Keep annualRate as a decimal inside the function (e.g. 0.07).
Why might this differ from Fidelity, Empower, or my employer site?
Live portals add fees, actual match formulas (true-up, vesting), fund order, auto-escalation, and YTD limit tracking. This page is one transparent story with the fields you set.
Is this investment or tax advice?
No. The numbers are a simplified illustration for learning and spreadsheet checks—not a fiduciary recommendation or filing position.