How the 401(k) Projection Works
The calculator projects monthly employee and employer contributions and compounds the modeled investment return over the time horizon you select. The chart separates your contributions, employer contributions, and modeled investment growth so you can see what drives the ending balance.
This is a growth projection, not a contribution-limit checker. IRS employee contribution limits, catch-up rules, employer-plan rules, taxes, fees, vesting, and investment returns can change, so compare your planned contribution with current plan and IRS guidance.
Employer matching can make a large difference because it adds contributions without reducing your own account contribution dollar for dollar, but match formulas vary. Some employers match only up to a percentage of pay, some use tiers, and vesting can affect how much of the employer contribution you ultimately keep. Use the calculator to understand the accumulation mechanics, then compare its match assumptions with the wording in your actual plan documents.
Frequently Asked Questions
Does this calculator enforce the current IRS 401(k) contribution limit?
No. It projects the percentage of salary you enter. Check the current IRS limit and your employer plan rules before using a contribution amount for real-world planning.
Why might my employer match differ from the calculator result?
Real plans can use caps, tiers, per-pay-period rules, true-up contributions and vesting schedules. The calculator follows the match assumptions you enter, not every plan rule.
Methodology & Related Tools
Review how RatioCalc builds, tests and updates calculator models before using an estimate for a material decision.
Accuracy review
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Site-wide consistency review: September 4, 2026.
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