How to use the multi-lift PR snapshot calculator
List each lift's PR load and the date you hit it, one per line, then add your body weight and a reference date. The page tabulates the bodyweight multiple and the weeks since each PR, names the lift that has gone longest without a new best, and adds a rep-by-rep conversion table so you can see what to load next session.
The bodyweight multiple is the PR divided by your body weight, and weeks elapsed is the gap between the reference date and the PR date divided by seven and rounded down. The conversion table shows Epley and Brzycki side by side. The two formulas disagree even from the same 1RM: at one rep Epley lands about 3% below the PR while Brzycki matches it, and past 10 reps the gap widens sharply (current as of October 2026). Neither is presented as the correct one.
This page does not predict when your next PR will land and it assigns no level or grade. The strength standards tables quoted online are self-reported percentiles from users of particular sites and the figures differ from site to site, so they cannot serve as a recognised standard. As a safety note, testing a true one-rep max carries injury risk, so building rep sets from the conversion table is the safer route.
Frequently asked questions
No. Rates of progress vary by person and by phase, so predicting a date from past records alone rests on weak ground. This page only shows a snapshot of where you are now.
This page assigns no level. The strength standards tables found online are self-reported percentiles from the users of particular sites, and because the figures differ between sites they are not a recognised standard.
That is how the Epley formula is built. It returns roughly 3% less than the 1RM at one rep, while the Brzycki figure in the same cell matches your PR exactly. That is precisely why both are shown.