1 repetition maximum1 repetition maximum (1 RP) is the maximum amount of weight that a person can possibly lift for one repetition.
Determining the 1 RP can be done directly through trial and error and simply requires the exerciser to complete one full repetition with the maximum weight possible.
Or you can estimate 1 Rp by using the formula:
1 RP = x*(1+y/30)
Where x stands for the amount of weights used and y for number of repetitions performed.