401K Calculator

A 401(k)’s single biggest advantage over an IRA, for most people, isn’t the higher contribution limit — it’s employer matching, literally free money added on top of what you contribute yourself. This calculator projects your account growth, though it’s worth understanding upfront exactly how to enter employer match correctly, since the calculator doesn’t have a separate field for it.

How the 401K Calculator Works

Enter your current age, planned retirement age, current 401(k) balance, monthly contribution, and expected rate of return before and during retirement, and the calculator projects your account balance forward using standard compound growth, then compares that projection against an estimated retirement income need to show whether you’re tracking toward a surplus or shortfall.

How to Correctly Include Employer Match in This Calculator

This is genuinely important to get right, since it directly affects the accuracy of your projection. This calculator has a single “monthly contribution” field, with no separate input for employer match — which means to accurately project your total account growth, you need to manually combine your own contribution and your employer’s match into one total figure before entering it. If you contribute $400 a month and your employer matches with an additional $200, enter $600 as your total monthly contribution, not just your own $400 — entering only your own contribution would significantly understate your actual projected balance, since employer match compounds right alongside your own contributions and represents real money that’s part of your account’s growth.

Why Employer Match Is Genuinely “Free Money” Worth Maximizing

Employer matching typically works as a percentage of your own contribution up to a specified limit — a common structure being “50% match up to 6% of salary,” meaning your employer contributes an additional 50 cents for every dollar you contribute, up to a contribution of 6% of your salary. Not contributing enough to capture your full available match means leaving guaranteed, immediate return on the table — a 50% match is effectively an instant 50% return on that portion of your contribution, before any investment growth is even considered, which is exactly why many financial advisors recommend contributing at least enough to capture the full employer match before directing additional savings elsewhere, including even a Roth IRA with its own separate tax advantages.

Why 401(k) Contribution Limits Are Higher Than IRA Limits

401(k) plans allow substantially higher annual contribution limits than IRAs, reflecting their design as a primary workplace retirement savings vehicle rather than a supplementary personal account. Like IRA limits, 401(k) limits are adjusted periodically and include an additional catch-up contribution allowed once you reach age 50 — verify the current limits directly with your plan administrator or the IRS, since this calculator doesn’t check your entered contribution against any specific limit and simply projects whatever monthly figure you provide.

Traditional vs. Roth 401(k): A Choice Some Employers Offer

Many employers now offer both a Traditional 401(k) (pre-tax contributions, taxed on withdrawal) and a Roth 401(k) option (after-tax contributions, tax-free qualified withdrawals) within the same plan — the identical fundamental tax trade-off as choosing between a Traditional and Roth IRA, just within a workplace plan with generally higher contribution limits. This calculator’s growth projection is identical for either type, since the underlying compound growth math doesn’t differ; the tax treatment difference matters for your actual retirement spending power, not the account balance projection itself.

Comparing Against IRA Savings

If you’re deciding how to prioritize contributions between a 401(k) and an IRA — commonly, maximizing employer match first, then considering a Roth IRA, then returning to maximize the 401(k) further — the IRA Calculator and Roth IRA Calculator project growth for those account types separately, useful for comparing total projected balances across a combined savings strategy spanning multiple account types.

Social Security as a Complementary Income Source

For most people, 401(k) savings are meant to supplement Social Security income, not replace it entirely. The Social Security Calculator illustrates that separate benefit formula, which combines with your projected 401(k) balance for a fuller picture of total expected retirement income.

Required Minimum Distributions on a Traditional 401(k)

A Traditional 401(k), unlike a Roth 401(k) in some cases, is subject to Required Minimum Distributions starting at a certain age. The RMD Calculator handles that separate, mandatory withdrawal calculation using the IRS Uniform Lifetime Table, relevant once you reach the applicable age for your Traditional 401(k) balance.

Frequently Asked Questions

How do I include my employer’s 401(k) match in this calculator?

Add your own monthly contribution and your employer’s match together into a single total, and enter that combined figure in the monthly contribution field. This calculator doesn’t have a separate field for employer match, so combining both manually is necessary for an accurate projection.

Why is employer match considered “free money”?

Because it’s additional money your employer contributes on top of your own contribution, typically as a percentage match up to a certain limit. Not contributing enough to capture the full match means missing out on that guaranteed additional contribution entirely, which represents an immediate return before any investment growth is even considered.

Should I max out my 401(k) or contribute to an IRA first?

A commonly recommended order is to contribute enough to your 401(k) to capture the full employer match first, then consider maxing out an IRA (often Roth, depending on your tax situation) for its own advantages, then return to your 401(k) for additional contributions if you can save more.

Does this calculator distinguish between Traditional and Roth 401(k) contributions?

No — the growth projection is identical for either type, since the underlying compound growth math doesn’t differ between them. The tax treatment difference affects your actual retirement spending power from the balance, not the projected balance itself.

Does this calculator check my contribution against IRS limits?

No — it projects whatever monthly contribution figure you enter without checking it against current 401(k) contribution limits. Verify your planned contribution against current IRS limits directly with your plan administrator or the IRS.