How is redundency calculated?

Heya, i work for a popular retail store in the UK im not alowed to state which one, but ive just found out that the store is not doing so well so they are getting rid of some people, ive been told my job is at risk and may be made redundant, im 22 years old, ive been with the company 5 years and im paid minimun wage 5.93, i work 39 hours a week, so im just wondering what sort of redundancy i would get, my manager does not know, he phones up HR today and said they would get back to him but i really need to know now as i have my consultation on tuesday and need to make a decision, ive tried loads of different redundancy calculators but they are all giving different answers, ive tried loads including direct gov, any hepl would be much apreciated, thankyou