This is a Single Page Application that has a few Sports Betting Calculators used for different purposes when trading in these markets. They can be utilised on any betting site, but most often tools such as Hedging and Dutching are used on the BetFair Exchange. The BetFair Exchange is where punters can trade different positions amongst themselves, and profit when their predictions are correct.
Let's look at some real time applications of these tools on the BetFair Exchange. Let's say you placed a back bet on Arsenal to beat Tottenham at the start of the match for £100 @ odds 2.50, and they score in the first half. Immediately the odds drop to 1.30 (signifying profit). With a normal bet your bet with Arsenal will stand until the match end, so you have to worry about Tottenham equalising. However, you could hedge out on your bet by covering all other outcomes, which in this case would be Arsenal not winning, i.e. lay against Arsenal. The Hedge calculator can tell you how much you need to lay to guarantee a profit regardless of whatever else happens. BetFair actually calculates this for you, but on non-Betting Exchanges you could use it.
The Arbitrage calculator is quite handy for people looking to take advantage of the different odds different bookmakers have. The idea is to find a price disparity between two bookmakers, and then covering a match outcome on each of them. The Arb calcuator does the Math for you to tell you how much you need to bet on each.