1RM vs 3RM vs 5RM
Your 1RM, 3RM and 5RM all measure the same underlying strength — they just use a different number of reps to get there. Here's how they relate.
What each term means
1RM
The heaviest weight you can lift for exactly one complete rep with good form.
3RM
The heaviest weight you can lift for exactly three reps — typically around 90-92% of your 1RM.
5RM
The heaviest weight you can lift for exactly five reps — typically around 85-87% of your 1RM.
Example: a 120 kg lifter
If your estimated 1RM is 120 kg, here's roughly what your 3RM and 5RM would look like using the Epley relationship in reverse:
| Rep max | Approx. % of 1RM | Approx. weight |
|---|---|---|
| 1RM | 100% | 120.0 kg |
| 3RM | ~91% | 109.3 kg |
| 5RM | ~87% | 104.3 kg |
Which should you test?
If you're newer to lifting, a 5RM is a safer way to gauge strength — the lighter relative load leaves more room to bail out of a bad rep. Experienced lifters preparing for a powerlifting meet will eventually need to practice true 1RM attempts, but even then, most of the training year is spent working with 3RM and 5RM efforts.
Use the one rep max calculator to convert any rep max — 1 to 20 reps — into an estimated 1RM.
Frequently asked questions
Is a 5RM safer to test than a 1RM?+
Generally yes. A 5RM requires a lighter weight relative to your max, giving you more reps to correct technique and reducing the consequences of a single bad rep.
Which rep max should I use to track progress?+
Whichever one you test most consistently. A rising 5RM over time reflects the same underlying strength gain as a rising 1RM — the calculator converts between them so you can track a single number either way.
Can I convert a 3RM directly to a 1RM?+
Yes — enter the weight and 3 reps into the one rep max calculator and it will estimate your 1RM using the Epley, Brzycki and Lombardi formulas.