See whether your savings are on track. Compare what you're projected to have at retirement against what you'll actually need to fund your lifestyle.
What You'll Have
What You'll Need
Projected shortfall of $43,691 — gap to close by age 67.
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10% of your monthly income
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70% of your current income (today's dollars)
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Social Security, pension, annuities
Advanced Assumptions
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During your working years the calculator compounds your current savings plus monthly contributions at your pre-retirement return rate, growing contributions each year with your income. That gives what you're projected to have at retirement. Separately, it calculates what you'll need: the lump sum required at retirement to fund your monthly budget — inflated to future dollars and net of Social Security or other income — all the way to your life expectancy, discounted at your post-retirement return rate.
The difference is your surplus or shortfall. If there's a gap, the calculator estimates the extra monthly saving needed to close it by retirement. All figures are hypothetical and ignore taxes and market volatility.
There is no single magic number — it depends on the lifestyle you want, where you live, and how long you expect retirement to last. But two frameworks make the target concrete.
This calculator uses your actual budget rather than a rule of thumb, projecting the exact lump sum needed to sustain your spending to life expectancy.
The years before retirement are when compounding does the heavy lifting. Each dollar you contribute in your 20s and 30s has decades to grow, which is why starting early matters far more than contributing large amounts later.
Three levers control how much you accumulate: how much you contribute, how long you contribute, and your rate of return. Of these, time is the most powerful because compounding is exponential — the balance in the final decade before retirement often grows more than everything contributed before it.
Once you retire, the math reverses: you withdraw from the portfolio while it (hopefully) keeps earning a more conservative return. The danger is running out of money before you run out of life, so the withdrawal rate matters enormously.
The classic 4% rule says a retiree can withdraw 4% of the starting balance in year one, then adjust for inflation annually, with a strong chance the money lasts 30 years. Longer retirements or early retirement argue for a more cautious 3–3.5%. Our calculator models the full drawdown month by month so you can see whether your projected savings actually last to your life expectancy.
A budget of $4,000 a month feels comfortable today, but at 3% inflation that same lifestyle costs about $7,200 a month in 20 years and roughly $9,700 in 30 years. Retirement plans that ignore inflation dramatically underestimate the nest egg required.
That is why this calculator inflates your desired budget to future dollars at retirement and continues growing it every year of retirement. Social Security benefits include annual cost-of-living adjustments, which is why they are such a valuable inflation-protected income source.
Personal savings rarely have to cover 100% of retirement spending. Guaranteed income sources fill part of the gap:
Enter the combined monthly total in the "Other monthly retirement income" field — every dollar of guaranteed income reduces the nest egg your own savings must provide.
If the calculator shows a shortfall, you have more options than just saving more:
How much do I need to retire?
A common rule of thumb is to save enough to replace about 70–80% of your pre-retirement income each year. Another popular benchmark is the 25x rule: aim for a nest egg roughly 25 times your expected annual retirement spending, which corresponds to a 4% initial withdrawal rate. This calculator does the math directly by projecting the lump sum needed to fund your monthly budget from retirement to your life expectancy.
What is the 4% rule?
The 4% rule suggests you can withdraw 4% of your portfolio in your first year of retirement, then adjust that dollar amount for inflation each year, with a high probability the money lasts about 30 years. It is a useful starting point, but it assumes a specific asset mix and historical returns. Lower withdrawal rates (3–3.5%) are safer for early retirees or long retirements.
Does Social Security count toward my retirement income?
Yes. Social Security, pensions, and annuities reduce the amount your personal savings must cover. Enter their combined expected monthly amount in the "Other monthly retirement income" field. The calculator subtracts it from your target budget so your required nest egg reflects only the gap your own savings must fill. The average Social Security retirement benefit is roughly $1,900–$2,000 per month.
Why does the calculator use different return rates before and after retirement?
Most people shift toward a more conservative, income-oriented portfolio as they approach and enter retirement, trading some growth for lower volatility. That is why a 6% pre-retirement return and a 5% post-retirement return are common defaults. You can adjust both in the advanced settings to match your own strategy.
How does inflation affect my retirement plan?
Inflation quietly raises your cost of living every year, so the budget you can live on today will cost much more decades from now. At 3% inflation, prices roughly double every 24 years. This calculator inflates your retirement budget to future dollars and continues growing it throughout retirement, which is why the required nest egg is larger than your budget alone might suggest.
What if I am behind on saving?
If the calculator shows a shortfall, it estimates the additional monthly contribution needed to close the gap by your retirement age. Other levers include working a few years longer (which both adds contributions and shortens the drawdown period), lowering your retirement budget, or increasing your expected return by adjusting your asset allocation. Even small increases compound significantly over time.