Compare spending now with the potential future value of investing the same one-time amount.
It turns the values and assumptions you choose into a transparent planning result. It does not import financial accounts, guess missing household information, or decide what is suitable for you.
The relationship
Follow the money, rate, and time basis
Potential future value = amount × (1 + entered annual return)^years; potential foregone growth = future value − amount.
Visual explanation
What the calculation is doing
Now123Futureentered change repeated over timePotential future value = amount × (1 + entered annual return)^years; potential foregone growth = future value − amount.
Read the result
Keep the result inside its assumptions
Spending 1,000 rather than investing it for 10 years at an entered 5% annual return has a modeled future value of about 1,628.89 and foregone growth of about 628.89.
Annual compounding is a hypothetical comparison. Returns can be negative, fees and taxes are excluded, and the result is not an investment recommendation or a claim that spending is inappropriate.
Quick guide
How to use this calculator
Enter one scenario with a consistent currency and the exact time basis shown by each label.
Treat growth, return, price change, and future contributions as assumptions rather than forecasts.
Use the component results and calculator-specific boundary to interpret the primary answer.
Calculation method
Calculation method
Potential future value = amount × (1 + entered annual return)^years; potential foregone growth = future value − amount.
Exact rational arithmetic is used where no compounding is needed. Bounded projections use stable logarithmic growth, deliberate decimal display rounding, overflow checks, and explicit unreachable states; a nonzero result is never replaced by zero.
Worked example
Worked example
Spending 1,000 rather than investing it for 10 years at an entered 5% annual return has a modeled future value of about 1,628.89 and foregone growth of about 628.89.
Potential future value = amount × (1 + entered annual return)^years; potential foregone growth = future value − amount.
Supported inputs
Precision and limits
Visible input limits
Amounts accept up to 30 digits and 12 decimal places and are capped at 1e12. Annual change is −100% to 1000%; projections use at most 100 years or 1,200 months, and a no-spend challenge at most 3,650 days.
International scope
No currency, tax, inflation rate, wage path, market return, withdrawal rule, price database, or recommended spending standard is assumed.
Projection boundary
Long-range results are deterministic illustrations of entered assumptions, not forecasts, guarantees, financial advice, or value judgments about spending and work.
Calculator-specific assumptions
Annual compounding is a hypothetical comparison. Returns can be negative, fees and taxes are excluded, and the result is not an investment recommendation or a claim that spending is inappropriate.
