HR Monitor Questions

WishfullDreamer

Does anyone know where I can get a less expensive heart rate monitor? Somewhere between $10-25. And how do they work exactly for showing your calories burned? Does it show all together till you stop it or something and could it work for going swimming? How would I use it when swimming? Reason I ask for swimming is because I plan on going swimming a lot this summer and joining swim team this summer/11th grade year. Also thinking about joining track so this would reallly help. Thanks in advance for your help.