How Much to Save for Retirement: A 4-Step Paper Method

Michael Chen

Michael Chen writes about personal finance fundamentals. Bay Area-based · finance enthusiast for 15 years.

Visual representation of the voice · not a photographic portrait

Quick answer: Estimate what you will spend each year in retirement, subtract what Social Security and any pension will pay, and multiply the gap by 25. That gives you a rough savings target in today's dollars. Then work out the monthly amount to reach it, and review the number with a fee-only fiduciary advisor before making big decisions.↗ Share on X

You can estimate how much you need for retirement with a pencil, a calculator, and four steps. Estimate your yearly spending in retirement, subtract what Social Security and any pension will pay you, and multiply the gap by 25. The result is a rough savings target in today's dollars. Then divide that target into a monthly savings amount.

This is an estimate, not a promise. Markets go up and down, prices rise, and life changes. But a rough number you understand is far more useful than a perfect number from software you don't trust. Below is the full method with a worked example you can copy.

Step 1: How much will you spend each year in retirement?

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Start with spending, not income. Your savings need to cover the life you actually live.

There are two ways to get this number:

The quick way. A common rule of thumb is that retirees spend about 70% to 80% of their pre-retirement income. If you earn $60,000 a year, that suggests $42,000 to $48,000 a year.

The better way. Look at your real spending today and adjust it line by line:

1. Pull up the last three months of bank and card statements.

2. Add up what you spent and multiply by 4 to get a yearly figure.

3. Remove costs that will likely end: commuting, work clothes, retirement contributions, and a mortgage if it will be paid off.

4. Add costs that often grow: health care, travel, hobbies, and home repairs.

Health care deserves special attention. Medicare usually starts at 65, but it does not cover everything. Premiums, deductibles, dental, vision, and hearing costs come out of pocket. If you plan to retire before 65, you will also need to pay for health insurance until Medicare begins.

Write down one number: your estimated yearly spending in retirement, in today's dollars.

Step 2: How much income will you get without touching savings?

Next, find the money that will come in on its own. For most people, that means:

• Social Security. Create a free account at ssa.gov to see your personal estimate at different claiming ages. Use the estimate for the age you actually plan to claim.
• A pension, if you have one. Your employer or plan administrator can give you an estimate.
• Other steady income, such as rental income or a part-time job you are confident you will keep.

Add these up for one year. Then subtract that total from your spending number in Step 1.

Spending − outside income = your yearly gap. This gap is what your savings must cover.

Step 3: How big does your nest egg need to be?

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Now multiply your yearly gap by 25.

Yearly gap × 25 = rough savings target.

Why 25? It comes from the widely used "4% rule." The idea is that withdrawing about 4% of your savings in the first year of retirement, then adjusting for inflation, has historically given a portfolio a good chance of lasting around 30 years. Dividing by 4% is the same as multiplying by 25.

Keep in mind the limits of this rule:

• It is based on past market history. The future can be different.
• If you retire early and need money for 35 or 40 years, a smaller withdrawal rate is safer. Multiplying by 28 to 33 instead of 25 builds in more room.
• If you are comfortable cutting spending in bad market years, the target can be a little lower.

A worked example you can copy

Let's follow "Sam," a 40-year-old who plans to retire at 65.

So Sam needs roughly $650,000 in today's dollars by age 65.

What about inflation?

Prices go up over time, so $650,000 in 25 years will buy less than $650,000 today. You have two simple ways to handle this.

Option A: Keep everything in today's dollars. This is the easiest. You plan in today's dollars and assume your investments grow a bit faster than inflation. In the next step we use a growth rate that already has inflation taken out, often called a "real" return.

Option B: Convert to future dollars. Multiply your target by an inflation factor. Assuming 3% inflation per year, the factors look like this:

For Sam, 25 years away: $650,000 × 2.09 ≈ $1.36 million in future dollars. That number looks scary, but it describes the same buying power as $650,000 today. Don't mix the two methods. Pick one and stick with it.

Step 4: How much do you need to save each month?

Here is a simple approach that stays in today's dollars and assumes a 4% yearly growth rate after inflation. That is a cautious assumption for a long-term mix of stocks and bonds, but returns are never certain, and some years will be negative.

First, see how much your current savings might grow on their own. Multiply what you have now by the growth factor for your timeline:

Then figure out the remaining gap and how much to save per year to fill it. Each $1,000 saved per year at 4% grows to roughly:

Sam's math:

1. Sam has $100,000 saved today. Over 25 years: $100,000 × 2.67 ≈ $267,000.

2. Remaining gap: $650,000 − $267,000 = $383,000.

3. Each $1,000 saved per year becomes about $41,600. So $383,000 ÷ $41,600 ≈ 9.2.

4. Sam needs to save about $9,200 per year, or roughly $770 per month.

Employer matching counts toward this. If Sam's employer adds $200 a month to the 401(k), Sam's own share drops to about $570.

Are you on track for your age?

If you want a fast reality check, one large investment firm suggests these savings milestones, measured as a multiple of your salary:

These are broad guidelines, not rules. Someone with a pension can need less. Someone planning to retire early can need more. Use them as a quick check, then trust your own four-step number.

What if the number feels impossible?

Many people finish this exercise and feel discouraged. You have more levers than you think:

1. Work a little longer. Each extra year adds one more year of savings, one less year of withdrawals, and a larger Social Security check if you delay claiming.

2. Capture the full employer match. It is part of your pay. Leaving it on the table means leaving money behind.

3. Raise your savings rate by 1% each year, ideally when you get a raise, so you never feel the cut.

4. Lower planned retirement spending. Paying off the house or moving somewhere cheaper changes the target a lot.

5. Plan for part-time income in the early retirement years.

6. Cut investment fees. Low-cost index funds, which simply follow a whole market instead of picking stocks, often charge much less than actively managed funds. Over decades, small fee differences add up.

When should you talk to a professional?

This method is a starting point. Please speak with a fee-only fiduciary financial advisor (someone legally required to act in your best interest and paid by you, not by commissions) if any of these apply:

• you are within 10 years of retirement;
• you have a pension with several payout choices;
• you have large savings in different account types and need a tax plan for withdrawals;
• you are deciding when to claim Social Security as part of a married couple;
• you have significant debt, health issues, or a family member who depends on you.

This article is general education, not personal financial advice. Your situation, taxes, and risk tolerance matter.

Your next step

Set aside 30 minutes this week. Log in to ssa.gov and write down your Social Security estimate. Then pull last month's bank statement and estimate your yearly retirement spending. With those two numbers, do Steps 2 and 3 on a sheet of paper. Once you have your target, compare it with what you save each month today, and adjust your 401(k) or IRA contribution so it moves you closer, even if the first change is only 1%.

FAQ

What is the 25x rule for retirement?

Multiply the yearly amount your savings must cover by 25 to get a rough target. It comes from the 4% rule, which suggests withdrawing about 4% of savings in the first year of retirement and adjusting for inflation after that.

Is the 4% rule safe for early retirement?

It was built around a retirement of about 30 years. If you expect a longer retirement, a lower withdrawal rate, such as 3% to 3.5%, leaves more room for bad market years.

Should I include Social Security in my retirement number?

Yes. Subtract your estimated Social Security benefit from your yearly spending before multiplying by 25. Get your personal estimate from your account at ssa.gov.

How often should I recalculate my retirement savings target?

Once a year is a good habit, and again after any big life change such as a new job, marriage, divorce, or a large change in expenses.

Educational content, not personalized financial advice. Sources cited where applicable.