Body Building and Weight Lifting Calc

The Weight Lifting and Body building calculator compute metrics for weight lifting including several different functions for one-rep maximums.  One-Rep Maximum calculator approximates the maximum weight a person can lift based on a set number of repetitions of a lesser weight. The calculator has several formulas for calculating the max weight.  See the descriptions of the different formulas below. 

Weight Lifting and Body Building Formulas

• Brzycki: Computes the approximate one-rep maximum weight one can lift using the Brzycki formula.
• Epley 1 Rep Max Formula: Computes the one repetition max using the Epley formula, the weight lifted and the number of repetitions.
• Landers Max Weight: Computes the approximate one-rep maximum weight one can lift using the Lander's formula, weight lifted and number of repetitions.
• Lombardi One Rep Maximum: Estimates the maximum amount of force that can be generated in one maximal lift based on the reps done on a lesser weight.
• Mayhew Max Weight: Computes the approximate one repetition maximum weight one can lift using the Mayhew formula.
• O'Conner one Rep Max Weight: Computes the approximate maximum weight one can lift using the O'Conner formula.
• Wathen Max Weight: Computes the approximate maximum one repetition weight one can lift using the Wathen formula.
• DAPRE Progression for Endurance: Computes the amount of weight you should lift for a given set to build endurance based on the target weight.
• DAPRE Progression for Endurance: Set 4 New Target Weight: Computes the target weight change (if any) for set four of a DAPRE Endurance workout.
• DAPRE Progression for Strength: Computes the amount of weight you should lift for a given set to build strength based on the target weight.
• DAPRE Progression for Strength: Set 4 New Target Weight: Computes the target weight change (if any) for set four of a DAPRE Strength workout
• Macronutrient Breakdown for Building Muscle
• IPF GL Coefficient Points Calculator: Computes the points associated with a comparative weight lifted between weight lifters based on the weight of the lifter (w), the weight lifted (x), the type of life and the gender of the lifter, all corrected by the International Powerlifting Federation Good Lift (IPF GL) Coefficient formula.
• IPF Good Lift Coefficient: Computes the comparative weight coefficient between weight lifters based on the weight of the lifter (x), the type of lift and the gender of the lifter, all combined in the IPF GL Coefficient formula.
• Simple Tait One Rep Max: Computes the approximate one rep max using the Simple Tait formula adjusted for RPE.
• Wilks Coefficient: Computes the comparative weight lifted coefficient between weight lifters based on the weight of the lifter and the gender of the lifter, all combined by the Wilks Coefficient formula.
• Wilks Coefficient Applied: Computes Wilks Coefficient formula value and applies it to Good Lift weight.

One-Repetition Maximum

Wikipedia writes the following in their definition of One-Repetition Maximum:
"One-repetition maximum (one rep maximum or 1RM) in weight training is the maximum amount of force that can be generated in one maximal contraction. One repetition maximum can be used for determining an individual's maximum strength and is the method for determining the winner in events such as powerlifting and weightlifting competitions. One repetition maximum can also be used as an upper limit, in order to determine the desired 'load' for an exercise (as a percentage of the 1RM)."

The following formulas can help you to calculate your one-repetition maximum:

Epley Formula
The Epley Formula, 1RM = w(1 + r/30), was presented by Boyd Epley in 1985 and is one of the simplest one-repetition maximum formulas available. This formula is similar to the Brzycki Formula, and for reps over 10, the Epley and Brzycki Formulas should yield the same answers. However, for reps below 10, the Epley Formula will provide a slightly higher maximum. Neither equation is 100% correct, but each one offers a baseline for weight lifting.

Source Lifting Revolution : http://www.liftingrevolution.com/strength-training-for-women-how-to-find-your-1-rep-max/ 

Wathen Formula
The Wathen formula  (1RM= 100w/ 48.8+53.8^-0.075r)  was computed by D. Wathen in 1994. This formula, just like the other six one rep max formulas, is used to calculate the amount of weight needed for weight lifting or body building. It has been confirmed to be accurate by Knutzen (1999) at predicting the amount of weight needed to an accuracy of 0.5 kg. 

Reference:
Cybulski, G., et al. Determination and Prediction of One Repetition Maximum (1RM): Safety Considerations. Journal of Human Kinetics. 2008. 19, 109-120.

Mayhew et al. Formula
The Mayhew et al. Formula can be found on Wikipedia. The Mayhew et al. formula is: (100*w/52.2 + 41.9*e^(-0.055*r)). It is used for accuracy in predicting the one-repetition maximum for dead lift, squat, and bench press. The details for the use of this formula, and the research behind it is found in the Wikipedia reference page. 

Wikipedia cites the use of the source: 

LeSuer, Dale A.; McCormick, James H.; Mayhew, Jerry L.; Wasserstein, Ronald L.; Arnold, Michael D. (November 1997). "The Accuracy of Prediction Equations for Estimating 1-RM Performance in the Bench Press, Squat, and Deadlift". Journal of Strength and Conditioning Research 11 (4): 211–213. doi:10.1519/00124278-199711000-00001.

The link to the Wikipedia page is:  https://en.wikipedia.org/wiki/One-repetition_maximum