Understanding Your 1RM
Your one-rep max is more than a bragging number — it's a tool for programming your training. Here's what it means, how to use it, and why you probably shouldn't test it.
What Is 1RM?
Your one-rep max (1RM) is the maximum weight you can lift for a single repetition with proper form. It represents your peak strength for that movement at that moment.
In practice, most people never need to actually lift their 1RM. Instead, they estimate it from a heavier set (usually 3-5 reps) and use the number to calculate training percentages. This is safer, more repeatable, and just as useful.
Training Zones by % of 1RM
This is the real value of knowing your 1RM — it tells you what weight to use for different goals.
90-100%
1-3 reps
Maximal Strength
Teaches your nervous system to recruit all available muscle fibres. Heavy and fatiguing — use sparingly.
80-90%
3-6 reps
Strength
The sweet spot for getting stronger without the injury risk of true maxes. Most of your heavy work should live here.
65-80%
6-12 reps
Hypertrophy
Optimal range for muscle growth. Enough load to stimulate the muscle, enough reps to accumulate volume.
50-65%
12-20+ reps
Endurance / Technique
Good for building work capacity, practising form, and warming up. Lower injury risk, higher fatigue.
Which Lifts to Track
You don't need a 1RM for every exercise. Focus on the big compound movements that form the backbone of your program.
Squat
Lower body strength benchmark. Tests quads, glutes, and core stability.
Bench Press
Upper body pressing benchmark. Tests chest, shoulders, and triceps.
Deadlift
Full posterior chain benchmark. Tests grip, back, glutes, and hamstrings.
Overhead Press
Shoulder strength benchmark. Harder to cheat than bench, good indicator of pressing power.
For isolation exercises (curls, lateral raises, etc.), just use a weight where you can complete the target reps with good form. No need for percentage-based programming.
Common Myths
You need to test your 1RM to know it
A calculated estimate from 3-5 reps is accurate enough for training. Testing maxes is high-risk, high-fatigue, and usually unnecessary.
Your 1RM is fixed
It changes with training, fatigue, sleep, nutrition, and even time of day. Think of it as a moving target — a snapshot of current capacity, not a permanent number.
Higher 1RM = better
Strength relative to your goals matters more than absolute numbers. A 120kg squat is impressive at 60kg bodyweight. Context matters.
You should train at your 1RM
Almost never. Training at 70-85% builds more strength with less injury risk. You get strong by accumulating volume at sub-maximal loads, not by grinding singles.
How to Estimate Your 1RM
Warm up properly
Work up gradually to a heavy weight. Don't jump straight to your working set.
Do a heavy set of 3-5 reps
Pick a weight you can complete with good form but is genuinely challenging. The last rep should be hard.
Plug into a calculator
Enter the weight and reps into the 1RM calculator. The formula averages multiple estimation methods for best accuracy.
Use the percentage chart
The calculator generates a percentage chart. Use it to pick weights for your training zones.
Use 1RM For
Calculating training percentages on compound lifts. Tracking strength progress over time. Programming periodised training cycles. Knowing what weight to put on the bar.
Don't Use 1RM For
Ego-testing every week. Isolation exercises (just use a challenging weight). Comparing yourself to others (bodyweight, training age, and genetics all differ).
The Bottom Line
Your 1RM is a programming tool, not a goal in itself. Estimate it, use it to pick weights, re-estimate every few weeks, and focus on the trend going up over months.