When you’re lifting, there’s always a balance: you want weights that feel challenging enough to make you stronger, but not so heavy that you burn out or risk injury. One of the best tools for finding that balance is your estimated one-rep max (e1RM).
Your 1RM is the maximum weight you could lift for a single rep with good form. But here’s the thing—you don’t have to test it directly to get value out of it. In fact, most of the time it’s better to estimate your 1RM from sets you’re already doing in training.
This helps you figure out a training range that’s just right: hard enough to build strength, without overreaching.
Why Estimate Instead of Test?
Testing a true 1RM takes a lot out of you. It’s fatiguing, sometimes risky, and not something you want to do every month. Instead, we can estimate your 1RM from a normal set—say, your last deadlift workout.
All you need is:
- The weight you lifted
- The number of reps you did
- How hard it felt (your RPE, or Rate of Perceived Exertion)
Plug those into a 1RM calculator (like this one from Barbell Medicine), and you’ll get a good estimate of your max.
Example: Estimating From a Deadlift
Let’s say you deadlifted 225 lbs for 5 reps at RPE 9 (meaning you felt like you had maybe one rep left in the tank).
Enter those numbers into the calculator, and you’ll see an estimated 1RM—something like ~265 lbs in this case.
That number becomes your anchor for training percentages.
Using Your e1RM to Guide Training
Once you have your estimated 1RM, you can figure out how heavy your working sets should be. Instead of guessing what “heavy” should be, these ranges give you structure. You’ll know, for example, that a strength set might be 80–85% of your e1RM—heavy, but not a grind.
The Role of RPE: Your Built-In Feedback System
Here’s where things get even better. RPE (Rate of Perceived Exertion) is how hard a set feels, based on how many reps you think you had left:
Click for RPE Chart
When you combine RPE with your e1RM, you get both structure and flexibility.
Example: If the program says “3 sets of 5 at 75%,” but today that weight feels like an RPE 9 (way too hard for where you’re at), you can adjust down. On the flip side, if it feels like an RPE 6 (too easy), you can nudge it up.
This helps you avoid overreaching—pushing too hard, too often—which stalls progress and raises injury risk.
How to Put This Into Practice
- Pick a recent lift (like your last deadlift session).
- Enter your numbers (weight, reps, RPE) into the Barbell Medicine calculator.
- Write down your e1RM in your training log or enter it into Train (our tracking app).
- Use percentages + RPE together to guide your lifts this month.
- Check in weekly: were your sets landing in the right RPE range? If not, adjust slightly.
- Re-estimate monthly: after a few weeks, plug in a new set to update your numbers.
Final Thoughts
Estimating your 1RM isn’t about chasing a big number—it’s about giving your training structure and feedback.
- Beginners: it keeps you in the right ranges as you learn the lifts.
- Intermediate and advanced lifters: it helps you fine-tune loads so you keep progressing without overdoing it.
So, grab your last deadlift session, run it through the calculator, and use your e1RM as your guide for the month. With practice, you’ll get better at using RPE, your training will feel more dialed-in, and your strength will keep climbing—without burning out.
