401(k) Starting From Zero Calculator
Estimate how monthly retirement contributions could grow over time using a simple long-term projection.
What this calculator helps you estimate
This calculator shows a simple projection of how monthly retirement contributions could grow over time. It starts from zero and uses an estimated annual return.
The point is not to predict the future perfectly. The point is to see how time, consistency, and investment growth can work together.
401(k) Starting From Zero Calculator
Estimate how retirement contributions could grow over time.
How to think about the estimate
Investment returns are not guaranteed. Some years may be positive, some may be negative, and the actual result may be very different from the estimate.
Still, calculators like this are useful because they show the relationship between time and consistent contributions.
Methodology and assumptions
This calculator starts with a $0 balance and models equal monthly contributions over the number of years entered. The annual return you enter is converted to a monthly rate and applied as a simplified compound-growth estimate.
The projection assumes a constant return and consistent contributions. Real investment returns vary over time. The estimate does not include employer matching contributions, plan or fund fees, taxes, inflation, contribution-limit changes, withdrawals, or changes to your contribution amount.
Do not treat the projected balance as a forecast or guaranteed outcome. It is a scenario for understanding how contribution amount, time, and assumed return interact.
Methodology reviewed September 20, 2026.
Common mistakes
Assuming the return is guaranteed: It is only an estimate.
Ignoring fees and taxes: Real accounts may have plan fees, fund expenses, and tax rules.
Waiting for perfect timing: For many people, the habit of contributing consistently matters more than guessing the perfect moment.