401(k) Fee Calculator

Worked example

With $100,000 saved, $10,000/year contributions, 7% gross return, and 1% fees for 20 years, the net 6% path ends meaningfully below the zero-fee path—the gap is fee drag.

When to use this

• Estimating long-term cost of plan and fund fees.
• Comparing two expense-ratio assumptions side by side.
• Preparing questions for an HR or plan provider fee disclosure.

Common mistakes

• Entering only fund ER and omitting plan administration fees.
• Assuming past returns already net of fees when they are gross.
• Ignoring that lower fees do not automatically mean better funds.

How it works

Compares a 401(k) projection at your gross expected return versus the same deposits at return minus annual fees. The difference is fee drag over the horizon.

Limitations

Results are estimates for educational purposes and are not financial advice. Actual fee schedules and returns vary.

Privacy and file handling

Your data stays on your device and is not uploaded.

Accuracy & methodology

This section documents how the calculator works, what it leaves out, and when results were last reviewed. Figures are educational estimates—not professional advice—and are not labeled "current" unless tied to automatically updated reference data.

Formula source or methodology

Annual compounding: balance = balance × (1 + netReturn) + contribution; compare gross vs net of fees.

Jurisdiction

United States (educational)

Unit system

US dollars and percents

Rounding method

Currency amounts round to two decimal places (half up via Math.round × 100 / 100).

Assumptions

• Constant annual fee percent and return
• Contributions at end of year

Known omissions

• Not tax, legal, investment, or lending advice. Confirm material decisions with qualified professionals.
• 2026 IRS contribution limits ($24,500 elective deferral; $8,000 catch-up age 50+; $11,250 catch-up age 60–63; $72,000 combined annual additions under §415(c), subject to applicable rules) — confirm plan documents; some tools enforce elective-deferral and §415(c) caps while others are estimate-only
• Employer match annual caps, true-up provisions, and vesting schedules
• Plan administrative fees and fund expense ratios unless a fee field is provided
• Inflation adjustment of future dollars (nominal dollars only unless stated)
• Income tax on withdrawals (pre-tax vs Roth treatment)
• Required minimum distributions (RMDs) and early withdrawal penalties

Test cases (automated)

• 1% fees reduce ending balance vs identical zero-fee path

Version & last verified

Logic version 1.0. Content and formulas last verified 2026-09-12.