401(k) Calculator: Estimate Your Retirement Savings Growth
A 401(k) calculator helps you project how your retirement savings will grow based on your contributions, employer matching, and investment returns over time. Whether you're just starting your career or approaching retirement, understanding your 401(k) growth is essential for a secure financial future. Use this free tool to see how small changes in your contribution rate or retirement age can dramatically impact your nest egg.
Your current age in years.
The age at which you plan to retire.
Your current annual gross salary before taxes.
The percentage of your salary you contribute to your 401(k) each year. The 2024 IRS limit is $23,000.
The percentage of your salary your employer matches (e.g. 3% means they match up to 3% of your salary).
Your existing 401(k) account balance, if any.
The average annual investment return you expect. Historically the stock market has averaged ~7% after inflation.
The average annual rate at which your salary increases. Typical value is 2–3%.
How often your investment returns are compounded.
Your results will appear here
How to Use This Calculator
1. Enter your current age and the age at which you plan to retire. 2. Input your current annual salary and set your contribution rate using the slider — this is the percentage of your salary you defer into the 401(k). 3. Enter your employer's match rate (check your benefits summary if unsure; a common match is 3–6%). 4. If you already have a 401(k) balance, enter it in the 'Current Balance' field. 5. Set the expected annual return (7% is a common long-term stock market average) and your anticipated salary growth rate. 6. Choose how frequently your investments compound. 7. Click Calculate to see your projected retirement balance, total contributions, employer match, and investment growth breakdown.
How the 401(k) Calculator Works
This calculator uses compound interest math combined with annual salary growth to project your 401(k) balance at retirement. It models contributions being made periodically (monthly, quarterly, or annually) and compounds investment returns at the same frequency.
The Core Formula
Each period, your new balance is calculated as:
- New Balance = Old Balance × (1 + r/n) + Periodic Contribution
Where r is the annual return rate and n is the number of compounding periods per year. Your periodic contribution is (Employee Contribution + Employer Match) ÷ n.
Salary Growth
As your salary increases over time, so do both your contributions and your employer's match (since both are percentages of salary). The calculator applies your salary growth rate at the start of each new year to reflect this dynamic.
Employer Matching
Employer matching is essentially free money added to your retirement account. If your employer matches 3% of your salary and you earn $60,000, that's an extra $1,800 per year going into your account. Always contribute at least enough to capture the full employer match.
Compound Interest Effect
The power of compounding means your investment returns earn returns of their own. The more frequently compounding occurs (e.g., monthly vs. annually), the faster your balance grows. Over a 30-year career, this difference can amount to tens of thousands of dollars.
Key Variables That Impact Your Balance
- Time horizon: The earlier you start, the more time compounding has to work.
- Contribution rate: Even a 1% increase in your contribution rate can add tens of thousands over a career.
- Rate of return: Higher returns dramatically increase the final balance due to exponential growth.
- Employer match: Maximizing your employer match is the highest guaranteed return available to you.