Gamble Calculator
Introduction
The Gamble Calculator implements ^{[1]}^{[2]}
 Dutching Calculator is a betting tool for smart betting on the internet.
 Double/Treble Calculator explains the usage of Double and Treble betting on multiple selections.
 Yankee Calculator is a useful tool for betting, but can not save you from losing.
The socalled Dutching Calculator calculates secure bettings (winners!):
 A 2way win, either A or B win, no alternatives.
 A 3way win, A or B win or both parties draw.
The Yankee Betting Calculator which implements:
 Singles
 Doubles
 Trebles
 Fourfold or Accumulator
 Lucky 15
Dutching means:
 The user gives his stakes and the bookmakers odds.
 The website calculates the results (win or lose).
Dutching Calculator
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. ^{[3]}
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. 
3way
Works exactly the same as the 2way but has one more option a draw as result.
Double/Treble
This form implements the following bets on multiple selections:
 Double(s)
 Treble(s)
The objective of a Double bet is to successfully pick out two winning selections across two different races on the same bet and stake, and in this case, you require both selections to win in order to achieve a return.
A Double bet is the most simple and straightforward multiple bet available.
As the name suggests, it is simply two different selections bundled together into one bet.
If the bettor makes two winning selections, they win and get a greater payout than they would if they have just placed two separate single bets.
A Treble' bet involves three selections on the same bet, picked from three different events, and the bettor requires all three outcomes to be successful in order to achieve a return from the bet.
If your selection consists on more than the require 2 (Double) or 3 (Treble) rows the bets are increased upon all the different combinations.
For a composition look at the table on Composition
Explanation
 In the above case all tree selected bets are winners.
 Because the double bet has been chosen there are 3 individual bets ( 12, 13 and 23)
 Therefore the total outlay is 3, 3 bets for the Stake per bet of 1)
 The total return is the sum of:
 For bet 12 : 2.01 x 1.90
 For bet 13 : 2.01 x 1.75
 For bet 23 : 1.90 x 1.75
 In total 10.66
 The total Profit is total return  total outlay = 10.66  3.00 = 7.66
Yankee Calculator
Please note: Currently the Each Way is not yet implemented.
The yankee is a 4 selection wager consisting of 11 bets:
 6 doubles,
 4 trebles,
 1 fourfold accumulator.
The yankee is rumoured to be named after an American soldier who placed a small bet in the UK and won back hundreds of thousands due to the multiple rollover mechanics at work.
Composition
Assume your bets consists on the results of 4 games 1, 2, 3 and 4, then the individual bets are:
Yankee Composition Parts  

Part  Selections (14)  Number of Bets 
Double  12, 13, 14, 23, 24, 34  6 
Treble  123, 124, 134, 234  4 
FourFold (Accumulator)  1234  1 
Total  11 
Usage
The input fields for the odds use the Decimal format and not American or Fractions. (See for explanation how to convert: https://www.timeform.com/betting/basics/oddsconversion).
Fill al the 4 requested odds and enter the Stake per bet.
Since a Yankee consists on 11 bets, a € 1.00 equals € 11.00 in total.
After filling the Stake per bet all calculations will be made.
See also
 Gamble Website, the website with the 23 way calculator.
 Beste Bookmakers, Beoordeling en websites van de beste bookmakers van Nederland (in Dutch).
Internal
 Gamble systemen for details and backgrounds in English and Dutch / voor details en achtergronden in Engels en Nederlands.
Reference
 ↑ Gamble systemen, gives detailed information on betting systems and background information in English and Dutch.
 ↑ TimeForm, Betting Guide for beginners.
 ↑ 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).