One-Rep Max (1RM) Calculator — Epley Method & Warm-Up
Calculate 1RM and build a warm-up
Enter a clean working set to estimate 1RM with Epley, see your training max (90%), grab quick targets, or build a warm-up to a confident top single.
1RM calculator for lifters: fast estimates, warm-ups & tips
This free one-rep max (1RM) calculator estimates your true single from a solid working set using the widely used Epley formula. Enter the weight and reps from a recent clean set and you’ll get an estimated 1RM in kg or lb, a practical training max (90%), and a quick % of 1RM table. You can also switch to the warm-up only tab, type a target 1RM, and generate a smooth sequence of sets that ramps from light technique work to a confident top attempt.
Why Epley? For sets of roughly 1–10 reps performed near technical failure, Epley offers a simple, repeatable predictor. It’s popular across powerlifting and general strength training because it behaves sensibly as reps change and doesn’t require velocity devices or special equipment. Still, all 1RM estimates are just that—estimates. Bar speed, sleep, stress, and skill can move your real-world single up or down on any day. Treat the number as a planning tool, not a trophy.
We show a training max (90% of your estimated 1RM) because many proven programs anchor work sets to that value. Running percentages off 90% reduces grindy reps, keeps technique crisp, and makes week-to-week progress steadier. The built-in table gives fast targets at 100–60%, and each row can send a weight straight into the warm-up builder.
- Good inputs matter. Use a clean set with a consistent range of motion. The closer to a true “last good rep,” the tighter the estimate.
- Technique first. Safeties or spotters on heavy sets; stop when form breaks. PRs are earned in training—tested on meet day.
- Units & precision. Choose kg or lb; outputs display to one decimal to make plate math easy.
- Progression. Most lifters grow best with lots of quality work at 65–85% plus 1–2 harder days weekly. Your warm-up should leave you ready, not tired.
How this 1RM tool works (Epley & warm-up)
Epley estimate: 1RM = weight × (1 + reps/30). Example: 100 kg × (1 + 5/30) = 116.7 kg. We also show TM = 90% of 1RM.
Percent table: Quick targets at 95, 92.5, 90, 85…60%. Tap a row to send that weight to the warm-up builder.
Warm-up: Progressive sets at ~40–95% leading to a single at 100%. Rest guidance is included; take longer before the top attempt.
1RM calculator FAQs
Is the estimate exact?
No estimate is perfect. Use consistent inputs, track trends, and let your bar speed and technique decide on the day.
Which lifts does this work for?
Bench press, squat, deadlift, overhead press, and similar compound barbell movements.
How often should I test 1RM?
Every 4–8 weeks is plenty for most lifters; progress training loads week-to-week using the table and training max.