Free tool

Character of effort calculator

Do one test set of 5 reps, stopping with 2 to 3 reps in reserve (never to failure). Enter it here and get your estimated max plus the load for each rep range.

Units

Test weight

Reps done

Reps left in the tank

Example: you lifted 90 kg for 5 reps and believe you had 3 more in you. The more honest your estimate, the better the numbers.

Your Training Max (estimated 1RM)

Weight you could lift for	% of max	Load

Example: if you do 4 reps with your 8-rep load, you finish with about 4 reps in the tank. Which loads, how many sets and how to progress them is what the programs plan for you.

An estimate, not a measurement. It starts from your own judgment of reps in reserve, which is less precise the further you are from failure, and people differ in how many reps they can do at a given percentage. If a set feels much harder or easier than planned, adjust the next one by 2.5–5%. Sources: Zourdos et al. 2016 (J Strength Cond Res), Helms et al. 2016 (Strength Cond J), Zourdos et al. 2021 (J Strength Cond Res).

Keep your numbers

Get the free 1RM Protocol (PDF)

The warm-up, the test set and the formula on a single page for your gym bag, plus an email when the programs open.