Gamble Calculator
The Gamble Calculator is a betting tool for smart betting on the internet. It calculates the revenues when betting on:
 A 2way win, either A or B win, no alternatives.
 A 3way win, A or B win or both parties draw.
The user gives his stakes and the bookmakers odds. The website calculates the results (win or lose).
2way
The Wrong idea
The idea is to enter 2 bets, One for winning, one for loosing, i.e. the change for red or black on roulette. ^{[1]}
You enter:
The result will show that you will loose (in the end) in all cases. See below. 
So that's is not the way to win and shows where this calculator is not helping you.
The Right idea
Now an example which shows how to do it right.
Suppose the winner of the Soccer World Champignons is Brasil (quote: 1.85) or Germany (quote: 2.54). Now you can always win by:
So you enter the following data:

The results is that
So in both cases you win a little money. When you higher the stake by multiplying both stakes with the same number, the profit also increase with the same multiplier. 
3 way
Works exactly the same as the 2way but has one more option a draw as result.
See also
 Gamble Website, the website with the 23 way calculator.
Reference
 ↑ Roulette: Red or Black: I know those changes are 18/37 for each color and 1/37 for zero (European Roulette) and 18/38 and 1/38 (American Roulette).