Retirement Calculator — Plan Your Financial Future
Estimate how much you need to save for retirement and what your monthly retirement income could be using the 4% rule. See also Savings Calculator and Compound Interest Calculator.
How the Retirement Calculator Works
This retirement calculator projects your savings growth from your current age to your target retirement age. It compounds your current savings and monthly contributions at the expected annual return rate, then applies the widely-used 4% rule to estimate sustainable monthly retirement income. The inflation adjustment shows what your retirement savings would be worth in today's purchasing power, giving you a realistic picture of your future financial position.
Retirement Savings Formula
FV = PV × (1 + r/12)^(12×t) + PMT × [((1 + r/12)^(12×t) − 1) / (r/12)]
Monthly Income = FV × 0.04 / 12 (4% rule)
Inflation-Adjusted = FV / (1 + i)^t
Where:
PV = Current savings, PMT = Monthly contribution
r = Annual return rate, i = Inflation rate, t = Years to retirement
Example Calculation
Current Age: 30, Retirement Age: 65 (35 years)
Current Savings: $50,000
Monthly Contribution: $500
Annual Return: 7%, Inflation: 3%
Retirement Savings ≈ $1,143,000
Monthly Income (4% rule) ≈ $3,810
Inflation-Adjusted ≈ $406,000 (today's dollars)
Retirement Savings Milestones
| Start Age | Monthly | At Age 65 (7%) | Monthly Income |
|---|---|---|---|
| 25 | $300 | $1,021,503 | $3,405 |
| 30 | $500 | $1,143,459 | $3,812 |
| 35 | $500 | $790,781 | $2,636 |
| 40 | $750 | $759,688 | $2,532 |
| 45 | $1,000 | $632,408 | $2,108 |
| 50 | $1,500 | $543,890 | $1,813 |
*Assumes $0 starting savings, 7% annual return, compounded monthly
Frequently Asked Questions
What is the 4% rule?
The 4% rule is a retirement planning guideline suggesting you can withdraw 4% of your retirement savings annually (adjusted for inflation) without running out of money over a 30-year retirement. It was derived from the Trinity Study analyzing historical market returns.
Is 7% a realistic annual return?
The S&P 500 has historically returned about 10% annually before inflation, or roughly 7% after inflation. A diversified portfolio of stocks and bonds might return 6-8%. More conservative estimates use 5-6%. The right number depends on your investment mix and risk tolerance.
How much do I need to retire?
A common rule of thumb is to save 25 times your desired annual retirement spending (the inverse of the 4% rule). If you need $60,000/year in retirement, aim for $1.5 million. This calculator helps you see if you're on track to reach your target.
Why does inflation matter for retirement planning?
Inflation erodes purchasing power over time. $1 million in 35 years will buy significantly less than $1 million today. At 3% inflation, $1 million in 35 years is worth about $356,000 in today's dollars. Always consider inflation-adjusted values when planning.
Solved Examples
Example 1: How much do you need to retire at 65 with $5,000/month income?
Solution:
Desired monthly income = $5,000, Retirement duration = 25 years (age 65-90)
Safe withdrawal rate = 4% per year (standard rule of thumb)
Annual income needed = $5,000 × 12 = $60,000
Retirement corpus = Annual income / Withdrawal rate
Corpus = $60,000 / 0.04 = $1,500,000
Verification: $1,500,000 × 4% = $60,000/year = $5,000/month
Answer: You need $1,500,000 saved by age 65 to withdraw $5,000/month for 25 years
Example 2: Monthly savings needed from age 30 to retire at 65 with $2M
Solution:
Target = $2,000,000, Years to retirement = 35, Expected return = 7%
Monthly Rate = 7% / 12 = 0.5833%, n = 420 months
PMT = FV / [(1 + r)^n − 1] / r
FV factor = [(1.005833)^420 − 1] / 0.005833 = 1,725.37
PMT = $2,000,000 / 1,725.37 = $1,159.13/month
Total contributed = $1,159.13 × 420 = $486,835
Growth from investments = $2,000,000 − $486,835 = $1,513,165
Answer: Save $1,159/month from age 30 — investments contribute 76% of the final amount
Example 3: Impact of starting at age 25 vs 40
Solution:
Goal: $1,500,000 by age 65, Rate = 7% annually
Starting at 25 (40 years): PMT = $1,500,000 / 2,637.87 = $568.62/month
Total invested = $568.62 × 480 = $272,938
Starting at 40 (25 years): PMT = $1,500,000 / 810.82 = $1,850.01/month
Total invested = $1,850.01 × 300 = $555,003
Starting 15 years later requires 3.25× more monthly savings
Answer: Starting at 25 requires only $569/month vs $1,850/month at age 40 for the same goal
Practice Questions
Try these on your own:
- Using the 4% rule, how much do you need saved to generate $80,000/year in retirement? (Answer: $2,000,000)
- You have $100,000 saved at age 35. At 7% growth, what will it be worth at age 65? (Answer: $761,226)
- Save $750/month from age 28 at 7% return. How much at age 65? (Answer: ≈$1,427,000)
- You need $1.8M to retire. At 8% returns starting from $0 at age 30, what monthly amount is needed? (Answer: ≈$902)
- At 3% inflation, what will today's $60,000/year lifestyle cost in 30 years? (Answer: ≈$145,636/year)
- You have $500,000 at retirement. At a 4% withdrawal rate, how much can you spend monthly? (Answer: $1,667/month)
Common Mistakes to Avoid
The biggest retirement planning mistake is not accounting for inflation. At 3% annual inflation, prices double every 24 years — meaning your $5,000/month lifestyle today will cost about $10,000/month in 24 years. Another critical error is withdrawing more than 4% per year in retirement, which risks running out of money before you die. Many people also underestimate healthcare costs in retirement; the average couple needs $300,000+ for healthcare expenses in retirement beyond Medicare. Waiting too long to start is the most costly mistake: delaying saving by just 10 years can reduce your final nest egg by 50% or more. Don't forget that Social Security alone typically replaces only 40% of pre-retirement income for average earners. Finally, being too conservative with investments while young (keeping everything in bonds or savings accounts) sacrifices decades of equity market growth that historically returns 7-10% annually.
Key Takeaways
- The 4% rule: save 25× your desired annual retirement income for a sustainable 30-year withdrawal.
- Starting at 25 vs 35 can mean needing half the monthly contribution for the same retirement goal.
- Always plan in inflation-adjusted dollars — add 2-3% annually to your target retirement income.
- Maximize employer 401(k) match first — it's an immediate 50-100% return on your contribution.
- Social Security replaces only 40% of income — you must save the remaining 60% yourself.
- Diversify between stocks (growth) and bonds (stability), shifting more conservative as you approach retirement.