How to choose your starting working weight

What the terms mean

Working weight — the weight you use for the main sets of an exercise.
Warm-up attempt — a light set before the working sets: it prepares the movement and helps you judge a weight without risk.
Reps in reserve — how many more reps you could have done with clean technique as you finished the set. “Did 12, 2 in reserve” means you could have done 14.
The 10–12 range — the working range for a beginner: to start, the ACSM recommends loads in the 8–12 rep zone; we use the upper part of the range so the first sets stay controlled.

Useful toolWorking weights calculatorWork out a working weight from your one-rep max and training goal.

Card: finding your working weight in 4 attempts

Print it and take it to the gym. Rest 1.5–2 minutes between attempts. The step percentages are a practical guide; the final criterion is reps.

0. General warm-up — 5–10 minutes
Easy cardio and joint mobility. Only move on to weighted warm-up attempts after this.
1. Attempt 1: the bar or the minimum — 10 reps
An empty bar or the machine's lightest weight. The goal here is range of motion and technique, not load.
2. Attempt 2: roughly +50% — 10 reps
Add about half of the first step. It should still feel light: “I could have done twice as many”.
3. Attempt 3: another +30–40% — 10 reps
Getting close to the working zone. If it is still easy, the next step up is your working attempt.
4. Working attempt: aim for 10–12 reps
Find a weight you can do for 10–12 reps with 1–2 in reserve. The possible outcomes are in the decision table below.
5. Record the result
Write down the weight, the reps and the reserve. The next session starts from this weight instead of hunting for it again.

Print the page (Ctrl/Cmd + P): navigation is hidden and the card remains.

Why you find the weight by attempts, not by guessing

Guessing the weight almost always misses: either it is too heavy and your technique breaks on the first reps, or it is too light and the set does nothing. Warm-up attempts solve both problems: a systematic review showed that a warm-up improves performance, and steps up from a deliberately light weight give a safe estimate of “where your working weight is”.

The algorithm uses percentages of the first step only as a guide to how quickly to add weight. The final criterion is always the same: 10–12 reps with 1–2 in reserve. If the gym has no small plates, or you are using dumbbells with large jumps, the algorithm still works — the steps are just coarser.

Decision table: what to do after an attempt

Check the result of each attempt against the table. The first three rows are the normal search; the last two are stop rules.

What happened	What it means	What to do
Did 12 reps and had 4 or more left in reserve	The weight is clearly light	Rest 2 minutes, add about 10% and do another attempt
Did 10–12 reps with 1–2 left in reserve	Working weight found	Record the weight and reps — this is your starting point
Stopped before 10 reps with clean technique	The weight is a little heavy	Drop about 10%, rest 2 minutes and repeat the attempt
Technique breaks even at a light weight	The problem is technique, not weight	Go back two steps and drill the movement; return to finding a weight next time
Sharp pain in a joint or muscle	A stop signal	Stop the exercise; if the pain does not pass, see a professional

Worked example: leg press machine

A beginner, first session. General warm-up — 5 minutes on the treadmill and some joint mobility.

Attempt 1: 40 kg × 10 — the machine moves freely, full range of motion.
Attempt 2: 60 kg × 10 (+50%) — still easy, “could have done twice as many”.
Attempt 3: 80 kg × 10 (+33%) — noticeably heavier, but technique is clean.
Working attempt: 95 kg — 12 reps, 2 in reserve → working weight found.

If the working attempt had left 4–5 reps in reserve, the table would call for another attempt — roughly 10% up. The result is recorded: the next session starts at 95 kg.

If you already know your working weight

The algorithm above is for an exercise you are doing for the first time. When your one-rep max is already known (measured or estimated), you can calculate a working weight from percentages: the working weights calculator rounds the exact value to the plates available, and the one-rep max calculator estimates a max from a working set.

Limits of applicability

The algorithm is for healthy adults starting an exercise that is new to them. It is a general guide, not an individual prescription.
The step percentages and the 1.5–2 minute rests are the editorial team's practical guidance, not a recommendation from a source: the sources set the criterion (8–12 reps, per the ACSM) and the benefit of a warm-up (the Fradkin et al. review), but not the specific attempt percentages or the pauses between them.
The search is done on machines or with a fixed technique you have learned with a coach or from a reliable model: attempts do not replace learning technique.
This material is not medical advice: injuries, pregnancy and chronic conditions are outside a general instruction and need a professional.

When to stop searching

End the session and get help for sharp pain, dizziness or chest tightness. Finding a weight while in pain is not adaptability, it is risk: come back to the search next time, one step lower.

What next

The working weight is found — now you need a plan to move it. Starter options: the 2-days-a-week beginner gym program or the home dumbbell program. All the options are in the programs catalogue.

Sources

The full list with access dates is in the “Sources and review date” block below. The main supports: the 2009 ACSM position stand (the 8–12 RM range for beginners and the 2–10% increase rule) and the 2010 systematic review with meta-analysis by Fradkin et al. (a warm-up improves performance).