Reps From Percentage Calculator

About this calculator

In strength training, your one-rep max (1RM) is the heaviest weight you can lift for a single complete repetition, and training programs are commonly prescribed as a percentage of that number — "work up to 5 reps at 80% of your 1RM," for example. Because the relationship between load and maximum achievable reps is well documented (heavier percentages allow fewer reps, lighter percentages allow more), tables like Prilepin's chart or the Epley/Brzycki rep-max formulas let you estimate roughly how many reps a given percentage should allow before failure.

Powerlifters, Olympic weightlifters and strength coaches use percentage-based programming because it scales automatically to each athlete's current strength level and removes guesswork from periodization — a coach can prescribe "70% for 8 reps" once and have it apply correctly to every lifter on the team, regardless of their individual 1RM. It's also how lifters plan deload weeks (lower percentages, same or fewer reps) and peaking blocks leading into a competition (rising percentages, dropping rep counts).

This calculator takes your 1RM and a target percentage and returns the corresponding training weight along with the expected rep range.