Retirement Math

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How much do you need to retire? Start with $10 a month — not $1 million. The Rule of 5% chart, easy compounding examples, and the one-page PDF.

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Retirement math is not a ticker. It is three questions. How much cash do you want each month when you stop working. How big a pile that requires. How a small amount, started now, becomes that pile.

You do not need $1 million to begin. You need a number you can skip this month — $10, $25, or $50 — and a place for it to sit. The three big rows that already live on this page ($1 million, $500,000, $250,000) are the finish-line ruler. The small-dollar tables are how you walk toward it.

A nest egg is the money you have invested for retirement — not the cash in a checking account. A withdrawal rate is the percent of that pile you spend each year so the pile can last. Compound interest is how a small habit becomes a pile: your money earns money, and then that new money earns money too. Inflation is why cash in a drawer shrinks. A dollar that buys a sandwich today buys less of one in twenty years.

This page is Jeff Rose’s Rule of 5% teaching chart — not a promise — plus compounding examples that start small. 8% in the tables is a classroom rate: a long-run stock-market teaching number, not a forecast and not a guarantee. Taxes, fees, and bad decades still exist. The point is to see the shape of the math before anyone sells you a 12% yield.

What these words mean

Nest egg means the invested pile. Withdrawal rate means how much of the pile you take as income. 5% of $10,000 is $500 a year, about $42 a month. 5% of $25,000 is about $104 a month. 5% of $50,000 is about $208 a month.

You can work the math backwards without a spreadsheet: monthly income × 12 ÷ 0.05 = the nest egg the ruler asks for.

Inflation means prices rise, so cash that sits still buys less. At 3% a year, $1,000 in a drawer buys about $744 of today’s goods in ten years, about $554 in twenty, and about $412 in thirty. That is why the pile needs to earn, not hide. The pile does not have to beat a brochure yield. It has to outrun prices and last.

Three levers move the pile: how much you put in, how long you leave it, and the rate it earns. You control the first two. The third, in this classroom, is 8% for the examples — not a promise. A 401(k) match is the one rate you can grab for free: $50 of yours plus $50 from work is $100 working before the market opens.

EXAMPLE — A CASHIER WITH $10 A WEEK

  • A grocery cashier puts $10 a week — about $40 a month — into a Roth IRA, a retirement account you open yourself with money you already paid tax on. She does not have $1 million. She has a paycheck and a skipped snack. After 30 years at 8%, $10 a week is about $58,907. On the 5% ruler that is about $245 a month later. After 40 years the same habit is about $124,347 — about $518 a month.

EXAMPLE — THE MATCH ON A SMALL WAGE

  • A warehouse worker earns $3,000 a month. The job matches 50 cents on the dollar up to 4% of pay. 4% is $120. He puts in $120. Work puts in $120. That is $240 a month into the pile — and he only “felt” $120. After 30 years at 8%, $240 a month is about $326,256. The match is the only free return in the building. Take it before you pick a ticker.

The Rule of 5% is a teaching chart, not a promise

Take 5% of the nest egg per year, as monthly income. The three rows that already live on this page are the ruler for bigger piles. Social Security, a pension, or rent from a house can sit underneath this number. The chart is the invested pile, not your whole life.

Nest egg 5% / year Per month
$1,000,000 $50,000 $4,167
$500,000 $25,000 $2,083
$250,000 $12,500 $1,042

You do not need those piles to start. Work the math backwards from a small paycheck. Monthly income × 12 ÷ 0.05 = the nest egg the ruler asks for. $100 a month is a $24,000 pile. $200 a month is $48,000. Those are finish lines a $25 habit can actually see.

EXAMPLE — WORK IT BACKWARDS

  • Want $100 a month? You need about $24,000.
  • Want $200 a month? You need about $48,000.
  • Want $400 a month? You need about $96,000.
  • Want $1,000 a month? You need about $240,000.

EXAMPLE — A MECHANIC WHO WANTS $200

  • A mechanic wants $200 a month of extra income on top of Social Security. The ruler says about $48,000. That is a finish line, not a starting balance. $50 a month for 30 years, at the classroom 8%, is about $67,970 — past that line. He does not begin at $48,000. He begins at $50.

EXAMPLE — A TEACHER WHO WANTS $400

  • A teacher wants $400 a month so a car payment disappears in retirement. The ruler says about $96,000. $100 a month for 30 years is about $135,940. $100 a month for 20 years is about $54,914 — only halfway. The extra decade is not a rounding error. It is most of the snowball.

Smaller piles on the same ruler — closer to a first decade of saving:

Nest egg 5% / year Per month
$10,000 $500 $42
$25,000 $1,250 $104
$50,000 $2,500 $208
$100,000 $5,000 $417

The chart is not a contract with the market. Stocks fall. Inflation rises. Taxes take a cut. Sequence of returns — a bad first decade of withdrawals — can shrink a pile faster than the average suggests. We still use 5% because the math is clean, and because a fund that shouts 12% needs a ruler next to it.

Start with $10, $25, or $50 a month

Nobody starts at $1 million. Most people start with a bill they can skip. A forgotten app. A streaming plan. Two cheap lunches. 8% here is a classroom rate — a long-run stock-market teaching number, not a promise. The table assumes you invest at year-end and leave it alone for 30 years.

$10 a month

One forgotten app

You put in (30 yrs): $3,600

Pile at 8%: $13,594

5% / month later: $57

$25 a month

One streaming bill

You put in (30 yrs): $9,000

Pile at 8%: $33,985

5% / month later: $142

$50 a month

Two cheap lunches

You put in (30 yrs): $18,000

Pile at 8%: $67,970

5% / month later: $283

$100 a month

A phone bill

You put in (30 yrs): $36,000

Pile at 8%: $135,940

5% / month later: $566

EXAMPLE — ONE FORGOTTEN $10 APP

  • Cancel a $10 add-on you forgot was billing. After 30 years you put in $3,600. The pile is about $13,594. On the 5% ruler that is about $57 a month — forever, if the pile lasts. After 20 years the same $10 habit is only about $5,491. The last decade does the heavy lifting. Small. Real. Better than zero.

EXAMPLE — ONE STREAMING BILL

  • Cancel one $25 subscription and invest it instead. After 30 years you put in $9,000. The pile is about $33,985. On the 5% ruler that is about $142 a month. After 40 years the same $25 is about $77,717 — about $324 a month. One bill. Four decades. A car-insurance payment in retirement.

EXAMPLE — TWO LUNCHES AND A WAITER

  • A waiter skips two cheap lunches a month and sends $50 to a Roth. After 10 years: about $8,692 — it still looks small. After 20 years: about $27,457. After 30 years: about $67,970. He put in $18,000. About $283 a month on the ruler. After 40 years the same $50 habit is about $155,434 — about $648 a month. Year 1 is $600. Year 40 is the punchline.

EXAMPLE — A NIGHT-SHIFT NURSE, $100

  • A night-shift nurse starts with $100 a month — one extra shift’s tip money. After 15 years at 8% she has about $32,583. After 30 years: about $135,940, and 5% is about $566 a month. She does not wait for a $10,000 bonus. When the raise comes, she does not upgrade the habit to a nicer car payment. She leaves the $100 in place and adds $25.

EXAMPLE — $5 A DAY, THE COFFEE NUMBER

  • $5 a day is about $150 a month. After 30 years at 8%: about $203,910. You put in $54,000. About $850 a month on the ruler. Nobody is saying skip every coffee. The point is scale. A daily number that feels like nothing is a yearly number the snowball can use.

EXAMPLE — $100 LEFT ALONE, NO EXTRA DEPOSITS

  • A teenager puts $100 from a first paycheck into an index fund and never adds another dollar. The Rule of 72 is a shortcut: divide 72 by the rate to guess the doubling time. At 8%, a pile doubles about every nine years. $100 becomes about $200, then $400, then $800. After 30 years that $100 is about $1,006. A seed without water stays a seed. Adding $25 a month is what turns a doubling trick into a paycheck.

Time beats a big first check. $25 a month for 40 years ($77,717) beats $25 a month for 20 years ($13,729) by a wide margin, because the late years are when the snowball is heavy. You cannot buy those years back with a hotter ticker.

How the $25 snowball looks, year by year

Year 1 of $25 a month looks like nothing: $300. That is the whole joke of compounding. It is boring at the start. It is not boring at year 30. Simple interest would add the same dollars every year and stop. Compound interest adds a percent of a growing pile, so each year’s interest is larger than the last.

Year You put in Pile at 8% 5% / month later
1 $300 $300 $1
5 $1,500 $1,760 $7
10 $3,000 $4,346 $18
20 $6,000 $13,729 $57
30 $9,000 $33,985 $142
40 $12,000 $77,717 $324

EXAMPLE — LEAVE IT VERSUS SPEND IT

  • If she spends the interest each year, the pile stays close to what she put in. If she leaves it, year 30 is about $33,985 on $9,000 of her own cash. Same $25. Two endings. Compounding is the decision not to spend the interest. DRIP — dividend reinvestment — is the same idea with extra steps: the stock pays a dividend, the broker buys more shares, the pile gets heavier. Turn DRIP off when you need the cash as income. That is the Rule of 5% moment.

Try $10 a month, $25 a month, or $50 a month on the chart. Default is $25 — a streaming bill, not a windfall.

How compound interest works. Two lines: reinvest vs spend the interest.

Classroom math: annual compounding, deposits at year-end.

Time beats a bigger check

Two people can put in very different cash and end in different places, because years compound and dollars do not get those years back. This is the comparison people skip when they wait to “invest later, when I can do it right.”

Start at 25

Habit: $50 a month for 40 years

You put in: $24,000

Pile at 8%: $155,434

5% / month later: $648

Start at 50

Habit: $200 a month for 15 years

You put in: $36,000

Pile at 8%: $65,165

5% / month later: $272

The 25-year-old puts in less ($24,000 vs $36,000) and finishes with more than double the pile. Starting late is not hopeless. Starting late with a small amount is slower. If you are 50, raise the monthly number. Do not wait for a perfect ticker.

EXAMPLE — A TRUCK DRIVER WHO STARTS AT 45

  • He can spare $100 a month, not $25. Fifteen years at 8% is about $32,583. Twenty years is about $54,914. That is not the $1 million row. It is a real $104–$229 a month on the 5% ruler, on top of Social Security. A start at 45 with $100 beats a plan to start at 55 with “more later.”

EXAMPLE — A TEENAGER’S FIRST JOB

  • $20 from each biweekly paycheck is $40 a month. Forty years of that habit, at 8%, is about $124,347 — about $518 a month on the ruler. She put in $19,200. The first job is the cheapest time to buy those years.

Where the $25 actually sits

Where the dollars sit beats which ticker you pick first. Fill the 401(k) match. Then a Roth IRA, if you qualify. Then a taxable brokerage. That is Start Here, step two. A Roth uses money you already paid tax on; qualified withdrawals in retirement are tax-free. A 401(k) often uses pre-tax pay, so the tax bill shows up later. Neither one is a stock. They are buckets. The fund inside the bucket is the next choice — usually a cheap, broad index, not a story stock.

Do not raid the pile for a vacation. That is spending next year’s interest today, and next year’s interest on that interest. A hardship exists. A want is not a hardship. Fees matter on a small pile too: a 1% fee every year is a slow leak. Cheap funds you understand beat fancy ones you cannot explain.

EXAMPLE — OVERTIME INTO THE MATCH

  • A clerk works one extra Saturday a month. After tax she clears about $75. She sends it to the 401(k). If work matches even part of it, the first-year “return” is the match, not the market. $75 a month for 30 years at 8% is about $101,955 — about $425 a month on the ruler — before counting any match. One Saturday. Not a second job forever.

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5% versus the 4% rule

The 4% rule comes from William Bengen’s 1994 work. Take 4% the first year, then raise the dollar amount with inflation. On $1 million that is about $3,333 a month. 5% is $4,167. Studies treated 4% as a 30-year survival rate, not a max-income target. 5% pays more now and leaves a thinner cushion if the first decade of retirement is ugly.

On the small piles this page actually starts with, the gap is easier to see. $10,000 at 4% is about $33 a month. At 5% it is about $42. $25,000 at 4% is about $83. At 5% it is about $104. $50,000 at 4% is about $167. At 5% it is about $208. The extra cash is the trade. This classroom teaches 5% as a ruler. It does not claim 5% always lasts.

EXAMPLE — SAME $25,000, TWO RULERS

  • A $25,000 pile is a decade of $50 a month, roughly, at the classroom 8%. 4% of that pile is about $83 a month. 5% is about $104 a month. Neither number replaces a job. Both numbers are a utility bill. That is what a first pile is for — a bill, then two bills — not a fantasy paycheck.

A 12% covered-call yield is not a paycheck

A covered-call ETF owns stocks and sells call options for extra cash. Headline yield is the big percent on the brochure. 12% on $25,000 looks like $250 a month. The 5% ruler on that same pile is $104. 12% on $50,000 looks like $500 a month. The ruler is $208. The gap is often NAV — net asset value, the real worth of one share — leaking while the checks look fat.

$25,000 at 5% $25,000 at 12% ad
Per month: $104 Per month: $250
What it is: The ruler. A planning number. What it is: Headline yield. NAV may leak.

EXAMPLE — THE BROCHURE VERSUS THE RULER

  • Compare JEPI, SPYI, and QQQI to this table before you treat the check as a paycheck. A high yield that eats the share price is a withdrawal in costume. We do not sell a 12% covered-call fantasy. How we get paid.

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Full ruler, large to small, including the original three rows:

Nest egg 5% / year Per month
$10,000,000 $500,000 $41,667
$8,000,000 $400,000 $33,333
$6,000,000 $300,000 $25,000
$5,000,000 $250,000 $20,833
$4,000,000 $200,000 $16,667
$3,000,000 $150,000 $12,500
$2,000,000 $100,000 $8,333
$1,000,000 $50,000 $4,167
$750,000 $37,500 $3,125
$500,000 $25,000 $2,083
$250,000 $12,500 $1,042
$100,000 $5,000 $417
$50,000 $2,500 $208
$25,000 $1,250 $104
$10,000 $500 $42

FAQ

Can I start investing with $10 or $25 a month?

Yes. $10 a month at 8% for 30 years is about $13,594. $25 a month is about $33,985. $50 a month is about $67,970. Start with a bill you can skip. 8% is a classroom rate, not a promise.

How much do I need to retire?

On the Rule of 5% ruler, $1 million is about $4,167 a month, $500,000 is about $2,083, and $250,000 is about $1,042. Write the monthly number you need, then read the chart. $200 a month of extra income is about a $48,000 pile. It is a teaching chart, not a promise.

What is the Rule of 5%?

Take 5% of your nest egg per year, as monthly income. Jeff Rose’s chart is the classroom ruler. Markets, inflation, and taxes still exist.

What is the 4% rule versus 5%?

The 4% rule takes 4% the first year, then adjusts for inflation — about $3,333 a month on $1 million. 5% is $4,167. On $25,000, 4% is about $83 a month and 5% is about $104. More cash now, thinner cushion. We teach 5% as a ruler, not a guarantee.

I am in my forties or fifties. Is it too late?

No. Time is the heavy lever, but a larger monthly number still works. $100 a month for 15 years at 8% is about $32,583. $200 a month for 15 years is about $65,165. Raise the habit. Do not wait for a perfect ticker.

Where do I put $25 a month?

Fill any 401(k) match first. Then a Roth IRA if you qualify — money you already paid tax on. Then a taxable brokerage. That order is Start Here, step two. The account beats the ticker.

Is a 12% covered-call ETF a retirement paycheck?

No. Headline yield is not a withdrawal rate. On $50,000, 12% looks like $500 a month; 5% is $208. On $25,000, 12% looks like $250; 5% is $104. Compare JEPI, SPYI, and QQQI to NAV, not the brochure.

How does compound interest grow a nest egg?

Your money earns money, then that new money earns money too. $25 a month at 8% for 30 years is about $33,985. You put in $9,000. If you spend the interest each year, the pile stays near what you put in. Compounding is the decision not to spend the interest. 8% is a teaching number, not a forecast.

Still building the pile? Walk Start Here in order. Accounts first. Options last.

$19 once. Six months of the desk.

Education only — not investment advice.