Opportunity Cost Calculator

Estimate the opportunity cost of spending money today vs investing it. See future value, lost growth, and break-even comparisons instantly.

Estimates only. This tool uses a simple compound growth formula and does not include taxes, fees, or investment risk.
Enter Your Scenario
Spend vs invest · opportunity cost
The money you spend today (or the amount you could invest instead).
OPPORTUNITY COST
$790.85
lost growth
Future value (Option A)
$1,791
Assumed return
6.0%
🧾

Breakdown

Amount (A)
$1,000
Return rate
6.0%
Years
10
Compounding
Yearly
Future value (A)
$1,791
Opportunity cost (lost growth)
$790.85
Tip: Try 3%, 6%, and 9% to see how sensitive the opportunity cost is to your return assumption.

How It Works

Opportunity cost is what you give up by choosing one option over another. In personal finance, the most common example is spending money today instead of investing it.

This calculator estimates the future value of money using compound growth and shows the “lost growth” (opportunity cost) over time.

  1. Amount: The money you spend today (or compare between two options).
  2. Return rate: Expected annual growth rate (e.g., 6%).
  3. Time horizon: How long you’d keep the money invested.
  4. Compounding: Yearly or monthly compounding can slightly change results.
  5. Inflation (optional): See results in today’s money (real value).

About This Calculator

Use this opportunity cost calculator to compare purchases, subscription decisions, or big financial choices like buying a car vs investing, paying off debt vs investing, or renting vs buying (as a rough estimate).

It’s not financial advice—just a fast way to visualize trade-offs and how compounding impacts your decisions.

  1. Best for: Quick comparisons and “should I buy this?” sanity checks.
  2. Not included: Taxes, fees, volatility, and personal risk tolerance.

FAQ

What is opportunity cost?

Opportunity cost is the value of the best alternative you give up when making a decision. If you spend money instead of investing it, the opportunity cost is the future value you could have earned.

How does this calculator estimate opportunity cost?

It calculates the future value of an amount using compound growth: FV = PV × (1 + r)^t. The opportunity cost is the difference between investing vs spending (or between Option A and Option B).

What return rate should I use?

Use a realistic long-term estimate. Many people test a range (e.g., 3%, 6%, 9%) to see how sensitive the result is to assumptions.

Is this financial advice?

No. This tool provides simple estimates. Real investing includes risk, fees, taxes, and uncertain returns.

Does it include inflation?

You can optionally include an inflation rate to see an inflation-adjusted (“real”) opportunity cost estimate.

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