Retirement Calculator
Plan your retirement timeline, nest egg growth, and safe annual withdrawal capabilities.
Calculator Variables
Calculation Overview
See if your retirement savings are on track. Estimate your future nest egg size, required wealth targets, and safe annual withdrawals.
Mathematical Model & Formula
Uses standard ordinary compound annuity metrics to compute what your savings will build to, then compares this total with a target retirement capital base calculated by scaling annual living expenditures by 25 (the reciprocal of the 4% rule).
- Annual Retirement Spending: Desired retirement cash outlays (adjusted back for inflation)
- Target Nest Egg: Required accumulated funds based on the 4% Safe Withdrawal Rule
Worked Example Scenario
Scenario: A 30-year-old with $50,000 saved, investing $1,000/month, wanting to spend $5,000/month starting at age 60 (30 years of growth) with 8% compound returns.
- Calculate compound principal over 30 years: $50,000 * (1.08)^30 = $503,132
- Calculate annuity growth: $1,000 * 12 * [((1.08)^30 - 1) / 0.08] ≈ $1,360,301
- Projected Nest Egg = $503,132 + $1,360,301 = $1,863,433
- Target Nest Egg for $5k monthly spending ($60,000/yr) = $60,000 * 25 = $1,500,000
Result: The user has a projected surplus of $363,433 above their retirement target.
Frequently Asked Questions
What is the safe withdrawal rate?
The percentage of your portfolio you can withdraw in your first year of retirement (and adjust for inflation each subsequent year) without running out of money over a 30-year horizon.
Academic & Regulatory References
- The Trinity Study - Safe Withdrawal Rates → The landmark academic research analyzing portfolio longevity across historical US market conditions.