1RM from Multiple Reps – Epley + Zones

This tool answers one practical question: how heavy can I go for a single? Type the weight and rep count of a recent multiple-rep set — say 5 reps at 60 kg — and the Epley formula projects your one rep max: 60 × (1 + 5/30) = 70 kg. It then converts that max into the three zones most programs use: 65% (45.5 kg) for technique and volume work, 80% (56 kg) for the hypertrophy-strength bridge, and 90% (63 kg) for heavy top sets. Worked example: a lifter doing 5×5 at 60 kg can expect a projected max of 70 kg, so adding load to 63 kg for triples stays safely within 90% while still building strength. Re-estimate every few weeks as your rep strength improves.

1. 1

   Enter weight and reps

   Any hard set of 2–10 reps works; 3–6 is most accurate

2. 2

   Read your 1RM

   The Epley formula projects your single-rep maximum

3. 3

   Grab your zones

   65/80/90% training zones are computed from the estimate

• 1

  Use the same lift and rep style every time you re-estimate

• 2

  Keep 1–2 reps in reserve on test sets for cleaner numbers

• 3

  Round zone weights to the nearest 2.5 kg for faster loading

• Feeding in a set with sloppy final reps

• Using this estimate to pick competition attempts

• Skipping re-estimation and stalling on old zone weights

• Confusing 80% of 1RM with 80% of your set weight