What This Calculator Does
This calculator is for US 401(k) retirement plans. It estimates how much you contribute to your 401(k) each year based on your annual salary and the percentage of pay you choose to defer, plus any employer matching contribution. Note that the IRS sets annual elective-deferral limits (for 2024, $23,000, or $30,500 if age 50+); this tool calculates the percentage-based amount and does not automatically cap to those limits.
How to Use It
Enter your gross annual salary, the percentage you want to contribute, and your employer's match percentage. The calculator returns your annual contribution, the employer match, the combined total going into your account, and an estimated per-paycheck amount based on 26 bi-weekly pay periods.
The Formula
Your contribution is simply salary multiplied by your contribution percentage: \(\text{Contribution} = \text{Salary} \times (\text{Contribution\%} \div 100)\). The employer match uses the same structure: \(\text{Match} = \text{Salary} \times (\text{Match\%} \div 100)\). \(\text{Total} = \text{Contribution} + \text{Match}\).
$$\text{Total} = \text{Salary} \times \frac{\text{Contribution \%} + \text{Match \%}}{100}$$
Worked Example
Suppose you earn $60,000 and contribute 6%, with a 3% employer match. Your contribution is \(60{,}000 \times 0.06 = \$3{,}600\). The employer adds \(60{,}000 \times 0.03 = \$1{,}800\). Total annual savings: $5,400. Spread across 26 paychecks, your own deferral is about $138.46 per paycheck.
$$\frac{\$3{,}600}{26} \approx \$138.46$$
FAQ
Does this include the IRS contribution limit? No — it computes a straight percentage of salary. Compare the result to the current IRS limit to ensure you stay within bounds.
Is employer match taxed now? Employer match goes in pre-tax and is not taxed until withdrawal in a traditional 401(k).
Why 26 pay periods? Many US employers pay bi-weekly, giving 26 paychecks per year. Adjust mentally if you are paid monthly (12) or semi-monthly (24).
