How the retirement calculator works
Each year until retirement, the calculator grows your existing balance by the expected return, then adds your contribution (a percentage of salary) and your employer's match. A typical match such as "50% of what you contribute, up to 6% of salary" is entered as 50% and 6%. Your salary rises each year by the increase you choose. Contributions are assumed to be added at the end of each year, which keeps the estimate slightly conservative.
The formula
Next balance = balance × (1 + return) + salary × contribution % + salary × min(contribution %, match limit %) × match %. The result is also shown in today's dollars by dividing by (1 + inflation)years, and as a first-year income using the 4% rule: 4% of the balance.
Example
Someone who invests $6,000 a year for 40 years at a 7% average return, starting from zero, ends up with about $1.2 million, of which only $240,000 was contributed. That is the power of decades of compounding — and why capturing the full employer match is often called free money.
2026 contribution limits
For 2026 the IRS limit on employee 401(k) deferrals is $24,500. Workers aged 50 and older can add an $8,000 catch-up contribution, and those aged 60–63 can add $11,250 instead. The calculator warns you if your contribution would exceed the base limit.
Frequently asked questions
What is the 4% rule?
It is a rule of thumb that withdrawing about 4% of your savings in the first year of retirement, then adjusting for inflation, has historically lasted around 30 years. It is a starting point, not a guarantee.
How much should I contribute?
At minimum, contribute enough to get the full employer match. Many planners suggest saving 10%–15% of income in total, including the match.
Are taxes included?
No. Traditional 401(k) withdrawals are taxed as income, while qualified Roth withdrawals are tax-free.
Does this include Social Security?
No. Social Security benefits would be in addition to the income from your savings.
Results are estimates for educational purposes only and are not financial, tax, legal or medical advice. See our disclaimer. Last reviewed 2026-10-22.