Retirement corpus calculator
Enter your current age, planned retirement age, life expectancy, current monthly living expenses, and expected return and inflation rates. The calculator computes the exact retirement corpus needed to fund your retirement years, adjusts your expenses for inflation, calculates your monthly savings requirement, and generates a year-by-year drawdown schedule. All calculations are performed client-side.
Calculates client-side · Estimates only · Not financial advice
Timeline & Expenses
Years old today
When you plan to stop working
Corpus planned to last until
Today's household budget needed per month
Existing portfolio / 401(k) / IRA balance
Market & Inflation Assumptions
Expected long-term cost of living growth
Expected portfolio return before retirement
Expected return during retirement (conservative)
$1,873,216
Total portfolio needed at age 65 to support 20 years of retirement with inflation-adjusted withdrawals.
$913/mo
Amount to invest each month for the next 30 years.
Expense & Investment Breakdown
Future Monthly Expense
$9,709
at age 65 (vs $4,000 today)
First Year Annual Budget
$116,509
12 months of inflated expenses
Current Savings FV
$503,133
compounded at 8.0%
Net Savings Gap
$1,370,083
remaining corpus to accumulate
Years in Retirement
20 years
Age 65 to 85
Real Return in Retirement
2.4%
net of 3.0% inflation
4% Rule Corpus (25x)
$2,912,715
Traditional safe withdrawal benchmark
3.3% Rule Corpus (30x)
$3,495,258
Conservative withdrawal benchmark
Year-by-Year Drawdown Schedule
Inspect the annual withdrawals and portfolio growth over your 20-year retirement.
Example
35-year-old retiring at 65
Current age 35, retiring at 65 (20 years in retirement to age 85) with $4,000/mo current expenses, 3% inflation, 8% pre-retirement return, and 5.5% post-retirement return: Future monthly expenses at age 65 are $9,709/mo ($116,509/yr). Total corpus required at retirement is $1,749,425. With $50,000 in current savings, required monthly savings today is $788/month.
Related: XIRR calculator, Break-even calculator, GST calculator
FAQ
- Is this retirement calculator financial or investment advice?
- No. This tool provides mathematical simulations based on user-supplied assumptions. It does not constitute financial, investment, or tax advice. Market returns and inflation vary unpredictably over decades.
- Does this calculator upload my personal financial information?
- No. All calculations run strictly in your browser tab. Plaintools has no server storage, analytics, or user tracking. Your figures never leave your device.
- How is the retirement corpus calculated?
- First, current monthly expenses are compounded at the annual inflation rate over the years until retirement. Then, the corpus is determined using the present value of an inflation-growing annuity during the retirement years, balancing annual withdrawals against investment returns in retirement.
- What is the 4% Safe Withdrawal Rule (Rule of 25)?
- The 4% rule (from the Trinity Study) suggests that withdrawing 4% of your initial portfolio in year one of retirement and adjusting for inflation each year historically sustained a 30-year retirement. The Rule of 25 is the inverse: target corpus = 25 × annual retirement expenses.
- How do I calculate retirement corpus without this page?
- Let T = retirementAge - currentAge, N = lifeExpectancy - retirementAge, i = inflationRate, r_post = postReturnRate, r_pre = preReturnRate. Future annual expenses E1 = currentMonthlyExpenses * 12 * (1 + i)^T. Real return r_real = (1 + r_post)/(1 + i) - 1. Required corpus C = E1 * (1 - (1 + r_real)^(-N)) / (r_real / (1 + r_real)). Compounded current savings S_T = currentSavings * (1 + r_pre)^T. Savings gap = max(0, C - S_T). Monthly investment SIP = gap * (r_pre / 12) / (((1 + r_pre / 12)^(T * 12) - 1) * (1 + r_pre / 12)). Estimate only; not financial advice.