Calculator
Enter your assumptions to estimate projected balance and whether your annual retirement spending goal may last through retirement.
How these estimates are calculated →Use the interactive model for the numbers, then use the sections below to choose better assumptions, interpret the result, and jump into the next question that usually comes up.
The projection estimates your 401(k) balance year by year from your current age through life expectancy. After retirement age, it models annual withdrawals against your spending goal so you can see whether savings may last.
Your savings rate, employer match, retirement age, and retirement spending goal usually matter more than tiny changes to market-return assumptions. The fastest way to learn from the tool is to compare a baseline scenario against one or two realistic improvements.
Use this calculator to stress-test a plan, compare tradeoffs, and understand whether your current savings path supports your target retirement lifestyle. Treat it as a planning model, not a prediction of actual market returns.
These are the most common planning questions that sit right next to the calculator. They help turn a raw projection into a better decision.
Contribution rate
A practical guide to choosing a 401k contribution percentage that fits your budget and goals.
Contribution rate is the biggest input lever in the model. Use this guide if you want a practical starting point before testing scenarios.
Open How Much Should I Contribute to My 401k? →Increase impact
If your real question is what an extra 1% to 5% adds, use the contribution calculator to isolate that single change before running a full projection.
If your real question is what an extra 1% to 5% adds, use the contribution calculator to isolate that single change before running a full projection.
Open Retirement by Age →Employer match
A straightforward breakdown of employer match mechanics so you can avoid leaving compensation behind.
If you are unsure how to enter your plan match, start here. Match structure can change your results more than small tweaks to return assumptions.
Open 401k Employer Match Explained →Tax treatment
How to choose between Roth and Traditional 401k contributions without guesswork or tax myths.
The calculator supports both Traditional and Roth balances, but this guide helps you think through the tradeoff before you model a split.
Open Roth vs Traditional 401k: How to Choose →Benchmark check
Use the retirement-by-age planner when your real question is not just what you may have, but whether your current path looks on track for your age.
Use the retirement-by-age planner when your real question is not just what you may have, but whether your current path looks on track for your age.
Open Retirement by Age →Focused answers for the questions most people have while entering assumptions or interpreting their result.
There is no single percentage that fits everyone, but the most useful starting point is usually the highest rate you can sustain while still capturing the full employer match. From there, compare scenarios with higher savings rates and annual step-ups to see how much they improve your retirement-income outlook.
Read the contribution guide →Use your plan's match percentage and cap as a simplified estimate. The model is directionally useful, but real plans can have true-up rules, vesting schedules, or payroll timing details that are more complex than a single flat match formula.
See employer match examples →Yes. You can model both current Roth balances and a Roth contribution split, which helps compare taxable and tax-free retirement income. If you are deciding between Roth and Traditional contributions, use the calculator alongside the tax-treatment guide rather than relying on a default split.
Compare Roth vs Traditional →It can show what your current plan may produce, but age-based benchmarks answer a different question: whether your balance lines up with common savings checkpoints for your stage of life. Use the benchmark planner if you want a faster directional check before or after running a full projection.
Open the benchmark planner →Use the contribution calculator when you want the marginal-impact answer. It isolates the increase itself and compares keeping it for 1 year, 5 years, or until retirement without turning into a second full retirement planner.
Open the contribution calculator →This model does not run Monte Carlo simulations, include taxes in retirement-income estimates, or capture every employer-plan detail. It is built to make assumptions visible and editable so you can compare scenarios clearly, then use the methodology page for the full explanation of what is and is not modeled.
Review the methodology →