How this instrument works
5/3/1 is a percentage-based strength program built by powerlifter Jim Wendler around a deliberately submaximal number called the training max, rather than a lifter's true one-rep max. This instrument does that first conversion: it takes a 1RM and multiplies it by 0.90 to get the training max, then works out the three sets that open the program's first week — 65%, 75% and 85% of that training max, the last of which is typically performed for as many clean reps as possible.
Working from 90% instead of 100% is the entire trick behind the program's longevity. A true 1RM already sits at the very edge of what a lifter can do on a good day, so building every week's math on top of it leaves no room for a bad night's sleep, a stressful week, or normal week-to-week strength fluctuation. Wendler's training max builds in that 10% cushion before the percentages ever get applied, so the resulting sets stay a notch below grinding-limit effort even in week one.
The wider 5/3/1 cycle keeps applying percentages of that same training max across three more weeks before a lighter deload: the second week typically runs 70/80/90%, the third 75/85/95% (the classic '5/3/1' rep scheme the program is named for), and the fourth backs off to roughly 40/50/60% to shed fatigue before the cycle repeats with a slightly higher training max. This calculator computes the training max and week 1 only — treat weeks 2 through 4 as the next steps once week 1 is dialled in.
- Enter One-rep max (1RM) — the heaviest single you (or a recent estimate) can lift for that exercise.
- Read Training max — 1RM x 0.90, the number every 5/3/1 percentage in the program is built from.
- Read Week 1, Set 1 through Set 3 — the three working weights for the program's first session on that lift, at 65%, 75% and 85% of training max.
- Round each set weight down to whatever your smallest loadable plate increment allows — the program is built around approximate percentages, not exact decimals.
- Set 3 in week 1 is conventionally an AMRAP (as many reps as possible) set, not a fixed rep target — use the calculated weight and push for quality reps.
Worked example — a 300 lb one-rep max
Enter 300 as the one-rep max. Training max comes out to 300 x 0.90 = 270 lb — the base every week-1 percentage below is calculated from. Week 1, Set 1 is 270 x 0.65 = 175.5 lb, Set 2 is 270 x 0.75 = 202.5 lb, and Set 3, the AMRAP set, is 270 x 0.85 = 229.5 lb.
Notice none of the three working sets comes anywhere near the original 300 lb 1RM — even the heaviest, at 229.5 lb, is roughly 76% of the true max. That gap is deliberate: it lets a lifter hit the AMRAP set hard for several reps beyond one, rather than grinding out a single near their absolute ceiling every week.
Questions
What exactly is a training max, and why isn't it my real 1RM?
The training max is a deliberately reduced number — 90% of a true or estimated one-rep max — that every 5/3/1 percentage is calculated from instead of the real max itself. Building the whole program on top of an actual 1RM would leave zero margin for an off day, so Wendler's system trades a small amount of raw percentage for a program that can be run week after week without constantly grinding at true-limit weights.
Why does the program use 90% specifically, not some other fraction?
Ninety percent is Wendler's chosen starting cushion: enough below a true max that even the heaviest set in a cycle still leaves reps in the tank, but not so conservative that the percentages feel too light to build strength. Some lifters run a slightly lower training-max percentage (85% or so) when recovery is compromised or confidence in their 1RM estimate is shaky, but 90% is the program's standard default.
What happens after week 1 — do the percentages change?
Yes. Week 2 conventionally moves to roughly 70/80/90% of training max for sets of 3/3/3+, week 3 (the '5/3/1' week the program is named for) moves to about 75/85/95% for sets of 5/3/1+, and week 4 is a lighter deload around 40/50/60% before the cycle restarts with a raised training max. This calculator computes the training max and week 1 only; treat those later weeks as the next step once week 1's weights are set.
How should I round the calculated set weights?
Round down to whatever plates you actually have — most lifters round to the nearest 5 lb (or 2.5 kg) increment their bar and plates allow. Rounding down rather than up keeps every set at or slightly under the intended percentage, which matters more for consistency across a training block than hitting the decimal exactly.
Does 5/3/1 only work for squat, bench, deadlift and overhead press?
Those four barbell lifts are what the program was built and is most commonly run around, since they're the lifts most people track a meaningful 1RM for. The underlying training-max-and-percentages math in this calculator works for any lift with a known or estimated one-rep max, but applying the full 5/3/1 progression scheme to accessory or machine work isn't standard practice.
How often should I recalculate my training max?
Typically at the start of each new cycle, once a deload week has passed — many lifters add a small fixed amount (5 lb on upper-body lifts, 10 lb on lower-body lifts is a common convention) to the previous cycle's training max rather than re-testing a fresh 1RM every time. Re-testing a true max periodically keeps that estimate honest, but doing it every single cycle isn't necessary.