Wealth Multiplier
Put a lump sum in, leave it alone, and watch it multiply. The simplest of our investing tools, it shows pure compounding and what inflation does to it. Add contributions with the Compound Interest Calculator.
1What you start with
$
A single lump sum, left to grow. No further contributions.
2Growth & inflation
% / yr
% / yr
3Highlight a yearOptional
years
Marked across the chart, the milestone bars and the table, for example your investing horizon.
Compound growth after 30 years7.6× your start
380,613
A single deposit at 7% a year, left untouched for 30 years, with no further contributions.
At 10 years98,358
At 30 years380,613
Real value at 30y181,454
30-year multiple7.6×
Growth over time
CompoundSimple interestReal value
$1.53M
$1.15M
$766k
$383k
$0
Year 25
now8y16y24y32y40y48y50y
Your money at each milestone
$70k
1.4×
5y
$98k
2.0×
10y
$193k
3.9×
20y
$271k
5.4×
25y ·
$381k
7.6×
30y
$749k
15.0×
40y
$1.47M
29.5×
50y
Your money doubles every
10.2 years
at 7% a year. So it is worth 4.0×+ after 30 years.
Inflation eats
52%
of the 30-year value. 380,613 nominal is worth 181,454 in today's money.
Year-by-year breakdown
Every year, compound against simple and real.
Each row is the year-end value: compounded, what plain simple interest would give, and the inflation-adjusted (real) value, with the multiple of your starting sum.
YearCompoundSimpleRealMultipleReal x
153,50053,50052,1951.1×1.0×
257,24557,00054,4871.1×1.1×
361,25260,50056,8791.2×1.1×
465,54064,00059,3761.3×1.2×
570,12867,50061,9831.4×1.2×
675,03771,00064,7041.5×1.3×
780,28974,50067,5441.6×1.4×
885,90978,00070,5101.7×1.4×
991,92381,50073,6051.8×1.5×
1098,35885,00076,8372.0×1.5×
11105,24388,50080,2102.1×1.6×
12112,61092,00083,7322.3×1.7×
13120,49295,50087,4082.4×1.7×
14128,92799,00091,2452.6×1.8×
15137,952102,50095,2512.8×1.9×
16147,608106,00099,4333.0×2.0×
17157,941109,500103,7983.2×2.1×
18168,997113,000108,3553.4×2.2×
19180,826116,500113,1123.6×2.3×
20193,484120,000118,0783.9×2.4×
21207,028123,500123,2624.1×2.5×
22221,520127,000128,6734.4×2.6×
23237,026130,500134,3224.7×2.7×
24253,618134,000140,2195.1×2.8×
25 ·271,372137,500146,3755.4×2.9×
26290,368141,000152,8025.8×3.1×
27310,693144,500159,5106.2×3.2×
28332,442148,000166,5136.6×3.3×
29355,713151,500173,8237.1×3.5×
30380,613155,000181,4547.6×3.6×
31407,256158,500189,4218.1×3.8×
32435,764162,000197,7378.7×4.0×
33466,267165,500206,4189.3×4.1×
34498,906169,000215,48010.0×4.3×
35533,829172,500224,94010.7×4.5×
36571,197176,000234,81611.4×4.7×
37611,181179,500245,12512.2×4.9×
38653,964183,000255,88613.1×5.1×
39699,741186,500267,12014.0×5.3×
40748,723190,000278,84715.0×5.6×
41801,133193,500291,08916.0×5.8×
42857,213197,000303,86917.1×6.1×
43917,218200,500317,21018.3×6.3×
44981,423204,000331,13619.6×6.6×
451,050,123207,500345,67321.0×6.9×
461,123,631211,000360,84922.5×7.2×
471,202,285214,500376,69224.0×7.5×
481,286,445218,000393,22925.7×7.9×
491,376,496221,500410,49327.5×8.2×
501,472,851225,000428,51529.5×8.6×
How to use this calculator
See your money multiply, in four steps.
1
Enter what you start with
In card 1, put in the lump sum you are leaving to grow. We prefill it from your net worth when you are signed in. Nothing is added after this; the tool is about a single deposit left alone.
2
Set growth and inflation
In card 2, set the expected annual return and the inflation rate. Return drives the compounding; inflation is what quietly erodes the purchasing power of the result.
3
Pick a year to highlight
Optionally set a custom year, say your investing horizon or the years until you turn 65, and it is marked across the chart, the milestone bars and the table.
4
Watch it multiply
Read the 30-year multiple, compare compound growth against simple interest and the inflation-adjusted line, and scan the milestone bars and full year-by-year table.
Key concepts
The mechanics of multiplying money.
Compounding
Each year you earn a return not just on your original money but on all the returns before it. That is why the curve bends upward instead of rising in a straight line: growth feeds on itself, and the later years dwarf the early ones.
The multiplier
The multiplier is simply how many times your money has grown: a 7.6x means a dollar became $7.60. It depends only on the rate and the time, not the amount, so it is the cleanest way to feel the power of a long horizon.
Compound vs simple interest
Simple interest pays the same fixed amount every year and grows in a straight line. Compound interest pays on the growing balance and curves away from it. The gap between the two lines is everything compounding adds, and it widens dramatically with time.
Real vs nominal
Nominal growth is the headline number; real growth strips out inflation to show what the money can actually buy. A pot that looks like it grew ten times might only buy five times as much. The real line is the one that matters for spending.
Doubling time
At a steady return, money doubles every fixed number of years, no matter how much you start with. At 7% that is about a decade. Knowing your doubling time turns an abstract percentage into something you can count on your fingers.
Time is the lever
Because the biggest gains land in the final years, starting earlier matters far more than starting bigger. A modest sum left for forty years routinely beats a larger sum left for twenty. The tool makes that asymmetry impossible to miss.
How many times money doubles in 30 years
Count doublings instead of dollars. At 7% money doubles roughly every 10.2 years, so 30 years holds almost three doubles: 2x, then 4x, then nearly 8x (the exact figure is 7.6x). At 5% a double takes about 14.2 years, so 30 years fits just over two, around 4.3x. At 10% a double takes only 7.3 years: four fit, and the multiplier reaches 17.4x. Notice what the last double does. It adds more than all the previous ones combined, which is why cutting a horizon short is so expensive.
Multiplier benchmarks at 5, 7 and 10%
A small reference table covers most planning conversations. At 5% a lump sum grows about 1.6x in 10 years, 2.7x in 20 and 4.3x in 30. At 7% those become 2.0x, 3.9x and 7.6x. At 10% they jump to 2.6x, 6.7x and 17.4x. Two things stand out: at these rates the third decade contributes more than the first two combined, and the seemingly modest step from 5% to 7% turns 4.3x into 7.6x. Set the inputs to any pair and the chart shows the gap.
Tips that compound
Getting the most from time.
Let it run untouched
Compounding rewards patience above all. Every withdrawal resets the curve to a lower path, forfeiting the outsized growth that only the later years deliver.
Know your doubling time
Divide 72 by your return for a quick estimate of the years to double, or read the exact figure here. It is the single most useful number for judging a long-term plan in your head.
Always check the real line
A big nominal number can hide a modest real one. Judge any long-term result by its inflation-adjusted value, which is what it will actually buy when you get there.
Start sooner, not bigger
An extra decade at the front of the curve usually beats a larger sum added later. If you can only do one, choose time over size.
Add contributions next
This tool grows a single deposit. To see what regular contributions add on top, move to the Compound Interest Calculator, which is the natural next step.
The rules of 114 and 144
The Rule of 72 has siblings: divide 114 by your return for the years to triple, 144 for the years to quadruple. At 7% that is about 16 and 21 years, close to the exact 16.2 and 20.5 this tool computes.
FAQ
Why does the curve bend upward instead of rising steadily?+
Because you earn returns on your returns. In year one you grow only your original deposit; by year thirty you are growing three decades of accumulated gains as well. That feedback is what makes the line curve, and why the last ten years of a long horizon add more than the first twenty combined.
What is the difference from the Compound Interest Calculator?+
This tool grows a single lump sum and nothing more, to isolate the pure effect of compounding and inflation. The Compound Interest Calculator adds regular contributions on top, and the Investment Return Calculator layers in fees, tax and withdrawals. Start here for the intuition, move there for a full plan.
How is the real (inflation-adjusted) value calculated?+
We take the nominal balance and divide it by inflation compounded over the same years. So a pot worth a nominal ten times your deposit, after 30 years of 2.5% inflation, is worth closer to five times in today's purchasing power. The real line is always below the nominal one, and the gap widens every year.
What is doubling time?+
The number of years it takes your money to double at a constant return, regardless of the starting amount. We compute it exactly as ln(2) divided by ln(1 plus your rate); the familiar Rule of 72 (72 divided by the rate) is a close mental shortcut. At 7% both land near a decade.
Does this include contributions, fees or tax?+
No, deliberately. It is the simplest of our investing tools: one deposit, one rate, left alone. That purity is the point, it shows compounding with nothing else in the way. For those frictions, use the related calculators, which build on this foundation.
Is a constant return realistic?+
It is a simplification. Real returns vary year to year and the average is never delivered smoothly. Here we hold the rate constant to show the shape of compounding clearly; treat the figures as illustrative, not a forecast.
How much does waiting ten years cost?+
Expressed as a multiplier, roughly half the final pot at typical rates. At 7% a lump sum left for 30 years grows 7.6x; invest the same amount ten years later and it only has 20 years, ending at 3.9x. The money you delay forfeits its final, largest double. The ratio is always the multiplier of the skipped years: 1.07 to the power of 10 is about 2, so each decade of delay divides the outcome by two.
What is a realistic return to enter?+
Honest ranges, not a single number. Diversified global stocks have averaged roughly 7 to 10% a year nominal over long periods, closer to 5 to 7% after inflation. A mixed stock and bond portfolio sits nearer 4 to 6% nominal, and savings accounts often trail inflation entirely. The 7% default reflects long-run equity averages before fees. If a plan only works above 10%, treat that as a warning, not a target, and test the downside by re-running at a lower rate.
What if inflation is higher than my return?+
Then the real multiplier falls below 1 and your purchasing power shrinks even while the nominal balance grows. At a 3% return with 5% inflation, the account shows 2.4x after 30 years, yet the real line shows about 0.56x: the money buys 44% less than the day you deposited it. The gap compounds just like growth does. Watch the real multiple column in the table; a nominal gain with a real loss is the quietest way to go backwards.
Why show a multiplier instead of a percentage gain?+
They carry the same information, but multipliers are harder to misread. A 660% total gain and a 7.6x multiple describe the identical outcome, yet percentages above 100 confuse many people (a 100% gain is 2x, not 1x). The multiplier also separates pace from destination: 7% describes a single year, while 7.6x tells you where 30 of those years actually lead. For comparing horizons or rates at a glance, times your money is the cleaner unit.
A single lump sum compounds at a constant annual return with no further contributions, fees or tax. The simple-interest line applies the same rate without compounding, for comparison. The real value deflates the compounded balance by the inflation rate over the same years. A constant return is a simplification; real markets vary. Figures are illustrative, not financial advice.
Single lump sum compounded at a constant rate. Real values deflated by inflation. No contributions, fees or tax. Illustrative, not advice.