401(k) Calculator
Project employee contributions, a capped employer match, salary growth, and investment growth in a 401(k).
Content updated August 2, 2026
| Year | Employee | Employer | Balance |
|---|---|---|---|
| 1 | $8,000.00 | $2,400.00 | $64,229.59 |
| 5 | $9,004.07 | $2,701.22 | $135,384.33 |
| 10 | $10,438.19 | $3,131.46 | $265,533.98 |
| 15 | $12,100.72 | $3,630.22 | $460,124.74 |
| 20 | $14,028.05 | $4,208.41 | $747,016.63 |
| 25 | $16,262.35 | $4,878.71 | $1,165,590.41 |
| 30 | $18,852.52 | $5,655.76 | $1,771,433.97 |
Projection before fees, inflation, taxes, withdrawals, vesting, and annual contribution limits. Confirm the match formula and eligibility rules in the employer's current plan documents.
A 401(k) balance can grow from three separate sources: money already invested, employee salary deferrals, and employer contributions allowed by the plan. This calculator keeps those sources separate so the effect of the match is visible.
Enter the plan's match as a percentage of employee contributions and the salary percentage where matching stops. Salary and contributions can increase annually, while all contributions are modeled at the end of each month using an equivalent monthly investment return.
The 401(k) formula
Employee = S×c; Employer = m×min(S×c, S×L); B₁ = B₀(1+i) + (Employee+Employer)/12S = annual salary · c = employee contribution rate · m = employer match rate · L = salary percentage eligible for matching · i = monthly rate equivalent to the entered effective annual return. B updates at each month end.
Worked example
Starting with $50,000, an $80,000 salary, a 10% employee contribution, a 50% match up to 6% of salary, 3% annual salary growth, and 7% annual return produces a 30-year projection of about $1,771,433.97. The model attributes about $380,603.33 to employee contributions and $114,181.00 to employer contributions.
Assumptions, rounding, and limitations
Assumptions
- Employee contributions equal a fixed percentage of the modeled annual salary and are spread evenly across 12 end-of-month deposits.
- Employer matching is deposited monthly at the entered rate on employee contributions up to the entered salary percentage.
- Salary increases once after each projection year and the annual return is converted to an equivalent monthly rate.
- All account, salary, and contribution amounts use the selected currency unit.
Rounding: The projection retains floating-point precision through monthly compounding and annual salary changes. Currency displays use up to two decimal places.
Limitations
- Supports balances and salaries up to 1 trillion, projection periods of 1–100 whole years, non-negative return and salary-growth rates up to 100%, and match rates up to 1,000%.
- Does not enforce IRS employee, catch-up, compensation, or total defined-contribution limits; test eligibility; model multiple plans; or calculate taxes.
- Excludes fees, inflation, investment losses, contribution timing differences, withdrawals, loans, vesting, forfeitures, and plan-specific definitions of compensation.
Sources
- 401(k) plans — Internal Revenue Service
- Matching contributions help you save more for retirement — Internal Revenue Service
- COLA increases for dollar limitations on benefits and contributions — Internal Revenue Service
How the employer match is capped
The annual employee contribution is salary multiplied by the employee contribution percentage. The calculator then compares that amount with salary multiplied by the plan's match-limit percentage and applies the employer match only to the smaller amount.
For example, a 50% match up to 6% of salary means the employer adds half of employee contributions until the employee has contributed 6% of salary. Actual formulas, eligible compensation, vesting, and deposit timing come from the plan document and summary plan description.
Why the projection does not enforce IRS limits
The IRS adjusts retirement-plan dollar limits and related compensation amounts over time. Participant age, plan type, other plans, and employer contributions can also change which limits apply.
This tool intentionally projects the amounts entered instead of silently clipping them to a rule that may not fit the user. Compare planned contributions with the current IRS limits and the employer's plan before acting.
Frequently asked questions
▶How is a 401(k) employer match calculated?
This model multiplies the employer match rate by the smaller of the employee contribution and the plan's stated matchable percentage of salary.
▶Does employer matching reduce how much an employee can defer?
The IRS explains that matching contributions do not reduce the employee salary-deferral amount, although separate annual limits can apply to employee and total plan contributions.
▶Does the result include vesting?
No. Employer contributions may follow a vesting schedule. The projection treats every modeled employer contribution as part of the displayed account balance.
▶Are fees, taxes, and inflation included?
No. The result is a nominal pre-fee projection and does not calculate current tax savings, withdrawal taxation, purchasing power, or investment expenses.
▶Does this enforce the current 401(k) contribution limit?
No. IRS limits can change and may depend on age and plan circumstances, so confirm the entered employee and total contributions against current rules.
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Open calculator →Disclaimer: 401(k) Calculator results are estimates for general information and education only, and are not financial, tax, legal or medical advice. Verify important decisions with a qualified professional.