Retirement Calculator: Nest Egg & 4% Rule

Calculated using standard mathematical and industry formulas.

Estimate total retirement accumulation and safe monthly withdrawal income using compound interest formulas and the 4% Safe Withdrawal Rate rule. Saving $600 monthly at 7% return over 30 years accumulates $1,098,565 in retirement savings, yielding $3,661 in monthly income.

How to use this calculator?

  1. Enter your current age and your planned retirement age.
  2. Enter your existing retirement portfolio balance across 401(k), IRA, and brokerage accounts.
  3. Enter how much cash you save and invest every month.
  4. Set your expected annual investment return (historically 7% to 10% for stock market index funds).
  5. Read your total projected retirement nest egg at age 65 and sustainable monthly income based on the 4% rule.

Formula & calculation method

Retirement Compound Interest & 4% Withdrawal Equations

Retirement Nest Egg A = P × (1 + r)^t + PMT × [ ((1 + r)^t - 1) / r ]; Safe Monthly Income (4% Rule) = (Retirement Capital × 0.04) / 12

r = monthly return rate, n = total compounding months until retirement age.

Step-by-step calculation example

Age 30 to 65 (35 yrs) with $50,000 initial + $500/mo @ 7% return → Projected Nest Egg: $1,407,242 (Generates $4,691/mo sustainable 4% income).

Key insights to remember

How to interpret your results?

The 4% Safe Withdrawal Rule (Trinity Study)

Withdrawing 4% of your initial portfolio value in year one (adjusted for inflation thereafter) historically sustains retirement spending across a 30-year horizon without depletion.

Expert advice & guidance

💡 Retirement tip: Boosting your savings rate by just 2% or postponing retirement by a single year exponentially increases safe monthly withdrawal income due to extended compounding.

Frequently asked questions

How much should I save for retirement?
Financial experts recommend saving at least 15% of your annual gross income toward retirement starting in your 20s or 30s. General milestones target saving 1x your annual salary by age 30, 3x by 40, 6x by 50, and 10x by 67.
What is an IRA (Individual Retirement Account) and how does it work?
An Individual Retirement Account (IRA) is a tax-favored investment account holding stocks, bonds, or mutual funds. Traditional IRAs offer tax-deductible contributions with taxed withdrawals, while Roth IRAs use after-tax funds for tax-free growth and withdrawals.
How much should I contribute to my 401(k)?
Always contribute enough to your 401(k) to claim 100% of your employer matching match (free money). Financial planners suggest escalating total 401(k) contributions to 10%–15% of gross annual salary over time.
How long will my money last in retirement?
Applying the 4% Safe Withdrawal Rate rule (withdrawing 4% of your initial retirement portfolio and adjusting for inflation annually) typically ensures your savings sustain your lifestyle for 30+ years without running out.

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