1RM Estimator – Submaximal Set Calculator

This estimator converts any hard working set into a projected one rep max so you can program training loads without maxing out. Enter a weight you moved for 1–12 reps and the tool runs the three most-cited prediction equations — Epley, Brzycki and Lander — and reports both the average and the spread between them. The spread is your honesty check: at 3–6 reps the formulas sit within about 5% of each other, while a 10-rep set can scatter by 10% or more. Worked example: a 120 kg × 3 squat averages to roughly 130.6 kg across the three formulas (Epley 132, Brzycki 129.6, Lander 130.1), so 90% work equals about 117 kg.

1. 1

   Log a recent set

   Use your heaviest clean set from the past two weeks

2. 2

   Read the projection

   Average 1RM plus the highest and lowest formula estimate

3. 3

   Plan loads

   Percentage guidance from 60% to 95% of the projected max

• 1

  Bookend estimates with an AMRAP set every 4–6 weeks

• 2

  Keep reps in the 3–6 window for the tightest formula agreement

• 3

  Log the same lift each time to compare trends

• Estimating from touch-and-go reps with bouncing or momentum

• Using a set with reps left in reserve, which lowballs the max

• Mixing kg and lb fields in the same calculation

• Comparing estimates across different lifts instead of the same lift