Retirement Calculator

Are you on track for retirement?

Retirement planning comes down to two questions: how big a nest egg will you need, and is your current saving pace getting you there? This calculator tackles the second question by projecting your balance at retirement from what you have today plus what you add each month. Pair that projection with a rough target, and you can see at a glance whether you are ahead, behind, or roughly on schedule — early enough to adjust while small changes still compound into big differences.

Retirement has two distinct phases. The accumulation phase is your working years, when contributions and compounding build the balance. The decumulation phase is retirement itself, when you draw that balance down for income. This tool models accumulation; the size you reach here becomes the starting point for the income you can sustain later.

How to use this calculator

Enter your current savings across all retirement accounts, your total monthly contribution, an expected annual return, and the years until retirement. The calculator compounds your balance monthly, separates the money you contribute from the growth on top, and charts the climb to your target retirement date. Run several scenarios — a higher contribution, an extra five years of work, a more conservative return — to see how sensitive the outcome is to each lever.

Two things this tool does not include: Social Security and pensions. Treat any such income as a supplement that sits on top of the balance shown here, reducing how much your own savings need to cover. Many retirees rely on Social Security for a meaningful slice of their income, but it is rarely enough on its own, so personal savings remain the part you control.

How much will you need? The replacement ratio

A common starting point is the replacement ratio — the share of your pre-retirement income you will want to replace each year, often estimated somewhere in the region of 70–85% because some work-related costs fall away. Multiply your expected annual spending by the years you expect retirement to last, and you have a rough target. Because nobody knows their exact lifespan, planning for a long retirement is the safer error.

How it's calculated

The projection rests on the future-value formula. A lump sum grows as FV = PV × (1 + r)ⁿ, where r is the periodic rate and n the number of periods; with monthly compounding the annual return is divided by 12 and years are multiplied by 12. Each monthly contribution is then future-valued over its own remaining time and summed in. Money saved early gets the longest runway to compound, which is why a head start outweighs a bigger deposit made late.

One force works the other way: inflation quietly erodes purchasing power over a multi-decade horizon. The balance shown is in nominal dollars, so a large number decades out will buy less than the same number today. To gauge real spending power, subtract your inflation estimate from the return you enter before projecting.

The 4% rule of thumb

To translate a nest egg into income, planners often cite the 4% rule as a rough guide: withdrawing about 4% of your balance in the first year of retirement, then adjusting for inflation, has historically had a good chance of lasting roughly three decades. Flip it around and it implies a target of about 25× your annual spending. It is a rule of thumb, not a guarantee — market conditions, fees, and how long you live all matter — but it gives a quick sanity check on whether a projected balance can support your desired lifestyle.

The saver who started at 25 contributed only four times as much as the one who started at 55, yet ended with roughly fifteen times the balance. That gap is the cost of delay — and the reason this calculator is most useful early.

Tips and common mistakes

• Don't ignore inflation. A seven-figure projection decades out may feel like plenty, but check what it buys in today's dollars before assuming you are set.
• Capture every contribution source. Include employer matches and all accounts in your monthly figure so the projection reflects your true saving rate.
• Plan for a long life. Underestimating your retirement length is one of the riskiest assumptions — outliving savings is harder to fix than over-saving.
• Revisit as you near retirement. Many people shift toward more conservative investments as they approach the finish line, which lowers the assumed return you should model.
• Treat the 4% figure as a guide. It is a starting point for conversation, not a guaranteed safe withdrawal rate for every market.