February 25, 2026

How to calculate your 1RM?

Calculating your 1RM (one-rep max) is one of the simplest hacks to stop training "by feel."

Because once you know your 1RM, you can:

choose your loads to the nearest % (strength, hypertrophy, endurance)
track your progress correctly
and above all, load intelligently on the movements that matter (squats, bench presses, etc.)

In this article, you will learn a reliable method for estimating your 1RM!

Let's go 🔥

What is 1RM?

The 1RM (one-repetition maximum) is the heaviest weight you can lift once, using proper technique and a full range of motion.

The problem?
Many people "calculate" their 1RM using a random formula... based on a set that is not at all representative... and end up with a useless (or even dangerous) number.

Why is it useful?

This is an objective basis for calculating your training loads as a percentage of 1RM.
you can track your progress
you plan your cycles better (strength → volume → intensification)

Method 1: Estimate your 1RM based on one set

The simple protocol

Choose a multi-joint movement (bench press, squat, deadlift, etc.).
Then do 1 reference set:
- between 3 and 10 repetitions
- close to failure (while maintaining good technique)
Calculate using an appropriate formula (see below).

The formulas to use

You don't need to use a lot. In practice,two are enough:

Epley: 1RM = load × (1 + reps/30)
Brzycki: 1RM = load × 36 / (37 − reps)

Which formula should you choose based on your reps?

If your set is...	Recommended formula	Why	Avoid if…
2-5 reps	Epley	Often stable when close to your max	You did a poorly executed rep.
6-10 reps	Brzycki	Widely used for moderate set	You have high muscular endurance (you can easily do 10 reps, but your actual 1RM is lower).

Complete example

You do 8 reps at 80 kg on the bench press, with clean form.

Epley: 1RM = 80 × (1 + 8/30) = 80 × (1 + 0.2667) = 80 × 1.2667 ≈ 101.3 kg
Brzycki: 1RM = 80 × 36/(37−8) = 80 × 36/29 = 80 × 1.2414 ≈ 99.3 kg

➡️ Your "useful" 1RM ≈ 100 kg (rounded).

And you can program your loads as a percentage.

Method 2: Test your true 1RM

Simple protocol

General + specific warm-up
Then several short sets, increasing the load
2-3 "serious" attempts max (otherwise you'll tire yourself out and underperform)

If you are testing your bench press, do not do it alone without safety measures or a spotter.

At home: having high-quality equipment is essential. A stable setup that can be upgraded to "rack" mode allows you to load heavier with more confidence.

Our standing pull-up bar + bar supports are designed to transform your setup into a more complete home gym (bench, squat, etc.).

1RM: what weights should you use?

Objective	% of 1RM (reference)	Typical rep zone	How to use it
Strength	85-95%	2-5 reps	Short sets, long rest periods, strict technique
Hypertrophy	70-80%	6-12 reps	Perfect for progressing and building volume

Tip: For many people, "classic" hypertrophy often falls around 70-80% of 1RM.

The 8 mistakes that skew your 1RM (and how to avoid them)

Set not representative (too easy/too far from failure) → aim for a tough, clean set.
Changing technique (bench bounce, shortened squat) → same range of motion, same tempo.
Too many reps (15-20+) → use a range, not a single number.
Exercise too "isolating" → formulas are more reliable on compound movements.
Fatigue/lack of sleep → your "daily" 1RM ≠ your actual level.
Sloppy warm-up → poor performance and high risk.
Week-to-week comparison under different conditions → compares similar sets.
Wanting a perfect figure → aims for a useful estimate for programming.

FAQ :

Which formula is the most reliable for calculating your 1RM?
For most people who work out: Epley (1-5 reps) and Brzycki (6-10 reps) cover 95% of needs.

How many repetitions can I use to estimate my 1RM?
Beyond 10-12 reps, the formulas diverge more. The best option is to stay between 3 and 10 reps.

Why does my 1RM vary from day to day?
Sleep, stress, nutrition, warm-up, motivation, and above all: technical quality. Always compare similar conditions (same exercise, same range of motion, etc.).

How often should you recalculate your 1RM?
It is a good idea to do this at the end of a block (e.g., every 6 to 12 weeks).

How can I use my 1RM to build muscle?
Set your main sets at around 70-80% of your 1RM, build up volume, increase reps or weight, and maintain strict form.

I hope you enjoyed this article!

Feel free to comment and share it if you do.

See you soon.

Eric Flag