Skip to content

What is my max, and which plates?

A one-rep max (1RM) is the heaviest weight you can lift for one repetition; a 1RM calculator estimates it from a heavier set of several reps. One set in. An estimated max out, with a percentage table and the discs for each side.

The set you did

kg
Formula
Show plates for

Estimates get less reliable as reps rise. This tool takes 1 to 12 reps, as the app does.

Estimated one-rep max

120kg

Epley · 100 kg × 6 reps

  • 95%about 1.6 reps115 kg
  • 90%about 3.3 reps107.5 kg
  • 85%about 5.3 reps102.5 kg
  • 80%about 7.5 reps95 kg
  • 75%about 10.0 reps90 kg
  • 70%about 12.9 reps85 kg

Per side at 85%

102.5 kg total

25 + 15 + 1.25

Your numbers in the formula

How the answer adds up.

One formula, applied to the set you did.

  1. Step 01

    The set

    100kg

    100 kg for 6 reps

  2. Step 02

    The formula

    1.2×

    100 × (1 + 6 ÷ 30)

  3. Step 03

    Your max

    120kg

    rounded to the nearest 2.5 kg

Reading the result

  • Where the formulas meet

    For a single, both return the weight itself, and they agree again at ten reps. From two to nine reps Epley reads higher; above ten, Brzycki does.

  • Percentages of the estimate

    The table shows common percentages of the estimate, rounded to 2.5 kg, beside the reps the chosen formula links to each one.

  • Plates assume a 20 kg bar

    And 25, 20, 15, 10, 5, 2.5 and 1.25 kg discs. Anything it cannot make exactly, it rounds down.

Formula and sources

Epley: 1RM = weight × (1 + reps ÷ 30). A single returns the weight itself, as the QuietGains app records it [1].

Brzycki: 1RM = weight × 36 ÷ (37 − reps) [2].

Reps run from 1 to 12, the range the app estimates from. The estimate rounds to the nearest 2.5 kg, and so does each row of the table.

Reps beside each percentage: Epley 30 × (100 ÷ percent − 1); Brzycki 37 − 36 × percent ÷ 100.

Plates: a 20 kg bar with discs of 25, 20, 15, 10, 5, 2.5 and 1.25 kg, heaviest first on each side and rounded down when the target cannot be made exactly, the method the app’s plate calculator uses.

Updated

  1. Epley B. Poundage Chart. Boyd Epley Workout. Lincoln, NE: Body Enterprises; 1985.
  2. Brzycki M. "Strength testing: predicting a one-rep max from reps-to-fatigue." J Phys Educ Recreat Dance 1993;64(1):88-90. doi:10.1080/07303084.1993.10606684

Your log already knows your max.

QuietGains tracks your estimated max from every set you log.

One essential cookie remembers this choice. Analytics run only if you allow them. Privacy policy