Financial education tool

What if you skipped that purchase?

See exactly how much an iPhone, AirPods, or daily coffee is really costing you - in future wealth you'll never have.

Try the calculator

Real purchase examples

25 real-life items teenagers and young adults actually buy - from iPhones to designer sneakers to Netflix.

Live market data

S&P 500 returns and inflation data pulled live from the Federal Reserve. Always accurate, never guesswork.

Bilingual & dual currency

Full English ($) and Hungarian (Ft) support. Perfect for international families and schools.

The calculator

Select one or more purchases, set how often you'd buy them, and see what that money becomes invested.

Select purchases - set how often you'd buy each

Custom amount ($)

Investment settings

Annual return 7.0%

Time horizon 20 yrs

Inflation rate 3.5%

Total invested

Invested value

Real value

Pure interest

Growth multiplier

Invested (compound) Just saved (no growth) Fancy item cost Real value of investment Real value if just saved

Select at least one item from the list above.

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Real-life examples

TV upgrade

Salary raise

Daily coffee

Bonus or windfall

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What this model assumes

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The formulas

Nominal invested value

FV = Σ C × (1 + r)^(n−k)
   k ∈ {0, f, 2f, …, n}

FV = future value  |  C = cash injection
r  = return rate   |  f = frequency (yrs)
k  = injection yr  |  n = time horizon

Real value

RV = FV / (1 + i)^n i = annual inflation rate

Real return — Fisher

r_real = (1 + r_nom) / (1 + i) − 1 ≈ r_nom − i (for small values)

Growth multiplier

M = FV / Σ C

Figyelj!

Ne csak számolj - tedd is meg.

Ha ezt most kihagyod, vagy az olcsóbb terméket veszed, a különbözetet tedd félre azonnal. Nyiss Lightyear számlát, tedd S&P 500-ba vagy alacsony kockázatú részvénybe, és felejtsd el 20 évre.

Lightyear számla nyitása →

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If this made you think twice...

compoundfor.me is free and always will be. If it helped, a coffee goes a long way.

You're a teacher

Use it in class to show students what compounding really means.

You're a parent

Showed it to your kid and something clicked? That's the goal.

You're just starting out

Fresh grad, first job - and now you're rethinking that purchase. Nice.

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