Opportunity Cost Calculator

Background.

Every choice closes a door. Taking one job means turning down another; leaving savings in a current account means passing up the interest a savings account would have paid; spending a Saturday fixing the car means not spending it on paid work or with family. Opportunity cost is the name for what sits behind the closed door, and it is the cost people most often forget to count, because it never appears on a receipt or a bank statement.

Businesses meet it constantly. An owner who works full time in her own shop without drawing a salary may see a profit in the accounts, but if that profit is smaller than what she could earn working for someone else, the shop is leaving her worse off. Economists call that a negative economic profit, even when the accounting profit is positive. Cash tied up in slow-moving stock carries the same hidden charge: whatever it could have earned elsewhere.

Here the idea is reduced to one subtraction — the benefit of the best option you passed up, minus the benefit of the option you took. A positive answer is how many dollars better off the alternative would have left you. A negative answer means your choice was the stronger one on the numbers.

The subtraction is only as fair as the two figures fed into it. They need to cover the same stretch of time, be measured the same way (both net of their own costs, both after tax if tax treats them differently) and carry similar risk. Anything without a price tag, from job satisfaction to a shorter commute, stays out of the result, and that is often where the real decision gets made.

What is opportunity cost calculator?

Opportunity cost is the value of what you give up by choosing one course of action over another. Economics textbooks usually define it as the value of the next-best alternative you did not take. This page reports the incremental version used in many finance settings: how much more the best rejected option would have delivered than the one you chose. Only the single best alternative counts, not the sum of every option on the table, and the answer is in dollars over whatever period both benefits describe.

How to use this calculator.

1. 01In Benefit from chosen option, enter the net dollar value of what you are doing or plan to do, after its own costs — for a job, the pay and benefits; for an investment, the expected return.
2. 02In Benefit from best forgone option, enter the same measure for the single best alternative you are turning down, not a total of every alternative.
3. 03Make the two figures comparable: the same time span, both before or both after tax, and, if the money arrives in different years, both converted to present value first.
4. 04Read the result. A positive figure is what the choice costs you on paper; weigh it against what the numbers leave out, such as risk, time and how much you would enjoy each option.

The formula.

Opportunity cost = benefit of best alternative − benefit of chosen option. Both terms are dollar amounts over the same period. A positive result is the amount you sacrifice by your choice; zero means the options are tied on the numbers; a negative result means the chosen option beats the alternative by that amount, so nothing measurable is given up. The arithmetic is a single subtraction, and both inputs may be negative — useful when comparing two ways of losing money, such as two loss-making product lines. The real work lies in the inputs. Each benefit should be net of its own costs, after tax where tax treats the options differently, and adjusted for timing and risk: a guaranteed $90,000 and an uncertain $90,000 are not the same thing. Effects you cannot price, such as strategic position or personal preference, stay outside the figure.

A worked example.

Frequently asked questions.

References& sources.

1. [1]OpenStax, Rice University. Principles of Finance, 2022. Chapters 6–10. Retrieved 2026-08-06.
2. [2]U.S. Internal Revenue Service. Tax guidance current 2026. Official forms, instructions and tax topics. Retrieved 2026-08-06.
3. [3]U.S. Securities and Exchange Commission. Investor.gov current 2026. Investment products and risk. Retrieved 2026-08-06.