Retirement Savings Calculator

About this calculator

This calculator projects how much you could accumulate by retirement given your current balance, monthly contributions, employer match, and expected investment return. Use it to see whether you are on track, to test how a higher savings rate changes the outcome, or to understand how inflation erodes the nominal balance over time.

How to read your results

The headline figure is your projected nest egg at retirement — shown in nominal (future) money by default. Toggle to "today's money" to see the same figure discounted by your assumed inflation rate, which is a better measure of real purchasing power. The stacked-area chart separates what you put in (your contributions), what your employer adds (match), and what the market contributes (growth), so you can see how compounding weight shifts from savings to earnings in later years. One caveat: the projection assumes a constant annual return, no market volatility, no taxes on growth, and no salary-based cap on the employer match — treat it as a planning guide, not a guarantee.

Worked example

Age 30, planning to retire at 65. Current balance: 10,000. Monthly contribution: 500. Employer match: 50%. Expected annual return: 7%. Inflation: 2.5%.

The calculator returns a nominal nest egg of 1,465,852. Your own contributions total 210,000, the employer match adds 105,000, and investment growth accounts for 1,140,852. Discounted at 2.5% inflation over 35 years, the inflation-adjusted value is 617,668 in today's money.

Frequently asked questions

What does "nominal" vs "today's money" mean?

The nominal figure is the raw future balance — the number of currency units you would have at retirement. "Today's money" (the real value) divides that by accumulated inflation, converting it to purchasing-power terms you can relate to now. At 2.5% inflation over 35 years the real value is roughly 42% of the nominal one.

How is the employer match calculated?

The match is modelled as a flat percentage uplift on your own monthly contribution: a 50% match turns 500 into 750 of monthly investment. Real plans usually cap the match at a percentage of your salary, but this calculator omits the cap because it does not collect salary data. If your match is capped, enter the effective match percentage you actually receive rather than the stated plan rate.

Does this cover the withdrawal phase?

No — it covers accumulation only. The projection stops at your retirement age. For a rough withdrawal estimate, the common 4% rule suggests you could draw about 4% of the nominal nest egg per year. That figure is not built into this calculator.

What return rate should I use?

Long-run historical average real returns for a diversified equity index have been around 6–7% nominal. A more conservative 5% accounts for a bond allocation or a shorter investment horizon. Avoid using the same return for both the nominal and inflation-adjusted toggle — the calculator handles inflation separately, so enter the nominal (gross) return you expect and use the real toggle to see the inflation-adjusted result.

Why does the inflation-adjusted value fall so far below the nominal?

Compounding works in both directions: at 2.5% per year, prices roughly double every 28 years. Over a 35-year horizon that means every unit of future money buys less than half of what it buys today, which is why the real value can be less than half the nominal figure.

How it's calculated

The calculator applies the future-value formula from src/lib/finance.ts with monthly compounding. Your current balance (PV) grows for n months at the monthly rate r = annual return / 12. Simultaneously, each effective monthly contribution (your amount plus the employer match percentage) is treated as an ordinary annuity — paid at the end of each month — and compounds for the remaining months. The two components are summed to give the nominal nest egg. The inflation-adjusted figure then divides the nominal result by (1 + inflation rate) raised to the number of years, using annual compounding. Total employee contributions, total employer match, and total growth are reported separately so you can see the composition of the final balance.