SuperCalc

Wealth Projection

Project where your money goes — building it up with compound interest, or drawing it down as retirement income. Switch modes, add inflation, watch the numbers shape your future.

Wealth planner

Wealth Projection

Project where your money goes — building it up, drawing it down, or both across your full timeline.

$
$
% / yr
years
% / yr

Common: 5–10% as your income grows. 0 to keep contributions flat.

Inflation (optional)

Adds a 'today's money' view so big future numbers are honest about lost purchasing power.

% / yr

0 to ignore

Your projection
Future value
—
Contributed
—
Returns
—
Multiplier
—

How compounding works

Compound interest is interest earned on previously-earned interest. Each month, the gain is computed on the current balance — which already includes prior gains. Over decades, this is dramatic: most of your final balance is growth, not contributions.

The standard SIP future-value formula is FV = C · ((1+r)n − 1) / r · (1+r), where C is the monthly contribution, r is the monthly rate, and n is the number of months. We compute this iteratively to handle starting amounts and reproduce a year-by-year breakdown.

In Spend mode, the same engine runs in reverse — the balance grows by returns each month, then shrinks by your withdrawal. We detect when the balance hits zero (depletion) and let you push that line back by adjusting inputs.

FAQ

What's the difference between Grow mode and Spend mode?
Grow mode (SIP/accumulation) projects how a recurring contribution compounds over time — building wealth. Spend mode (SWP/decumulation) projects how a corpus depletes as you withdraw from it — drawing down. Same math, different direction.
How does inflation affect the projection?
In Grow mode, inflation is a viewing transformation: the math is unchanged, but you'll see your final value in today's purchasing power alongside the nominal number. In Spend mode, inflation grows your monthly withdrawal each year so you maintain real spending power — this changes the cash flow.
What's a safe withdrawal rate?
The classic 4% rule says you can withdraw 4% of your starting corpus annually (adjusted for inflation) and reasonably expect a 30-year retirement to survive. The tool surfaces your withdrawal rate as one of the four insight tiles — under 4–4.5% is the sustainability zone for long horizons.
What's the compound crossover year?
The first year your investment returns (the gain on your portfolio) exceed your contributions (the new money you put in). After this point, your money is doing more work than you are — that's when compounding really takes over.
Are the projections guaranteed?
No projection of future returns is. The tool assumes a constant annual return; real markets are volatile. Use it as a planning aid — try a few return rates (e.g., 6%, 8%, 10%) to bracket reasonable outcomes.
Are my numbers stored anywhere?
Only in your browser's local storage so they survive a refresh on this device. The calculation request itself goes to a stateless API — nothing is logged.

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