How to calculate retirement
Income = Nest egg × 4% ÷ 12 Today’s dollars = future savings ÷ (1 + inflation)^years Monthly real income = real savings × 4% ÷ 12 + other monthly income
Worked example. Your nest egg at retirement: $1,342,857.
Example inputs — Current age: 30; Retirement age: 65 years; Current savings: $25,000; Monthly contribution: $800; Annual return: 6%; Expected inflation: 3%; Desired monthly income: $0.00; Other monthly retirement income: $0.00. Starting values are illustrative.
From George Guju, founder of Calculyn · Educational calculator guidance, not professional advice.
How it works
We project your savings forward with monthly contributions and compound growth, then illustrate monthly income at 4% of the projected balance per year. This withdrawal heuristic is not a guarantee of safe income. Optional income targets and other retirement income are entered in today’s dollars. Inflation discounts the projected balance for this income comparison.
Using the retirement estimate
Retirement planning connects what you save now with what you may need later. A projected balance is a starting point for that discussion, not proof that you can retire on a particular date. Use the timeline, savings and return assumptions shown in this calculator to compare a baseline plan with a more conservative scenario and a higher-contribution scenario.
Step-by-step inputs
- Current age. Replace the starting value with your own, keeping the displayed unit and period. Starting example: 30 .
- Retirement age. Replace the starting value with your own, keeping the displayed unit and period. Starting example: 65 years.
- Current savings. Replace the starting value with your own, keeping the displayed unit and period. Starting example: $25,000 .
- Monthly contribution. Replace the starting value with your own, keeping the displayed unit and period. Starting example: $800 .
Worked example with the starting values
Using the starting inputs, the estimate is Your nest egg at retirement: $1,342,857 .
- Monthly income (4% rule)
- $4,476
- Total contributions
- $361,000
- Growth
- $981,857
- Savings in today’s dollars
- $477,229
- Monthly income in today’s dollars
- $1,591
Make a useful comparison
Keep existing savings separate from future contributions. Include only accounts you intend to use toward the goal and avoid adding the same balance through multiple inputs. A projection becomes more useful when the starting figure matches current statements.
Test changes in retirement timing and contribution levels before relying on a higher return. An additional year can mean another year of deposits and another year of modeled growth, but your ability to work or save for that year is still an assumption.
Check whether a goal is expressed in future dollars or today's purchasing power. Inflation can make a large future balance buy less than the same number buys now. Use the inflation calculator alongside a nominal projection to put the target in context.
Common mistakes to avoid
- The model does not know your complete retirement income, healthcare needs or tax situation. Pension income, public benefits and account withdrawal restrictions require separate attention.
- A steady return path hides the risk of poor market performance near retirement. A single average return does not describe the sequence of real gains and losses.
- A projected balance alone does not establish a sustainable withdrawal amount. Before making a major decision, compare spending needs, reserves, tax treatment and a range of investment outcomes.
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Assumptions & limitations
- A constant rate of return or inflation every year.
- Excludes fees and taxes unless entered.
- Contributions are made regularly and on time.
Formula and assumptions reviewed October 2026 by the Calculyn team. How we build our calculators
Frequently asked questions
How much money do I need to retire comfortably?
Start with annual spending minus reliable retirement income, then model how your savings might cover the gap. Dividing that gap by 0.04 illustrates a 4% starting withdrawal, not a guaranteed safe target; taxes, healthcare and longevity also matter.
What is the 4% rule and is it still useful?
It is a historical planning heuristic: withdraw 4% of the initial portfolio in year one, then adjust that dollar withdrawal for inflation. This tool only illustrates 4% of its projected balance divided by 12; it does not simulate market sequences or guarantee 30 years of income.
Should I prioritize a 401(k) or a Roth IRA?
Compare any employer match, fees, investment choices, eligibility and your current versus expected retirement tax position. An employer match can be valuable, but account selection needs your plan details; this projection does not optimize contribution order.
How does inflation affect retirement planning?
Inflation reduces what a future dollar buys. This retirement calculator shows nominal future dollars without automatically adjusting expenses for inflation. Compare purchasing power with the inflation calculator and avoid subtracting inflation twice.
Am I behind on retirement savings for my age?
Age-based savings benchmarks are only rough comparisons. Your planned retirement age, spending, pension or other income and contributions matter more than age alone. Test your own timeline and several return assumptions.
Are retirement calculators accurate?
They calculate the stated assumptions consistently, but future returns and expenses are uncertain. This tool assumes steady growth and regular deposits, and omits taxes, fees and market volatility. Treat the result as a scenario rather than a forecast.
How often should I use a retirement calculator?
Revisit it at least when income, contributions, investments or retirement plans change. A periodic annual check can help track progress without treating short-term market moves as a new long-term forecast.
Does reaching the projected balance guarantee retirement readiness?
No. Readiness also depends on spending, other income, taxes, healthcare, investment risk and how long the money must last.
Why compare several scenarios?
Small changes in returns, timing and contributions can accumulate over decades. Comparing them shows which assumptions your plan depends on most.