The opportunity cost calculator works out opportunity cost — inflation adjusted, forgone investment earnings and total savings (after tax) from income tax, annual inflation rate, annual return on savings, money to spend and investment period. Enter what you have and the relationship is applied straight away, so you get the answer without working through the algebra yourself.
What Is the Opportunity Cost Calculator?
The opportunity cost calculator takes income tax, annual inflation rate, annual return on savings, money to spend and investment period and turns them into opportunity cost — inflation adjusted, forgone investment earnings and total savings (after tax).
It is the kind of calculation you would otherwise do on the back of an envelope: mechanical, repeatable and easy to get subtly wrong without noticing.
How the Opportunity Cost Figure Is Built
Each result is calculated from the ones before it, so the working is fully visible. That matters when the answer is going to be quoted to somebody else and you need to be able to explain where it came from.
The figures are exactly as good as the assumptions underneath them. Check the rates, the periods and the tax treatment before you rely on the result.
Reading the Result Sensibly
A small change in an input can move the result by much more than you would expect, particularly where the calculation divides by one of the figures you supplied. That is worth understanding before you rely on a figure.
For anything that will be committed to, write the inputs down beside the result. A number you can reproduce is worth far more than one you cannot explain.
A Worked Example
Working through an example, with income tax set to 10, annual inflation rate set to 5, annual return on savings set to 2, the calculator returns nominal opportunity cost of 122.12, and forgone investment earnings of 22.12, and tax on capital gains of 2.21. Substitute your own figures and the same steps produce the same kind of answer.
Frequently Asked Questions
What do I need to work out opportunity cost — inflation adjusted?
Enter income tax, annual inflation rate, annual return on savings, money to spend and investment period. The calculator then works through the relationship and reports opportunity cost — inflation adjusted, forgone investment earnings and total savings (after tax).
What does the opportunity cost actually calculate?
It takes income tax, annual inflation rate, annual return on savings, money to spend and investment period and converts them into opportunity cost — inflation adjusted, forgone investment earnings and total savings (after tax) using the standard relationship for this problem. Each step is applied in turn, so every output is traceable back to the numbers you typed in.
How should I enter income tax?
Use the value you actually have, in the unit shown next to the field. Enter every value in the same unit system. The calculator assumes the figures you supply are consistent, so it cannot correct a mistake that happens before the calculation starts.
Do I have to fill in every field?
Only the fields a particular result depends on. If you leave one blank, the results that need it simply show a note instead of a number, and everything else still works.
Is the answer exact?
It is as exact as the formula and the inputs allow. The method itself is the standard one for this problem, so the only sources of error are the figures you enter and the precision you ask for.