Question 1

What is a one-rep max (1RM)?

Accepted Answer

Your one-rep max is the maximum weight you can lift for a single repetition with proper form. It's used to program training percentages, track strength progress, and compare lifters.

Question 2

How accurate are 1RM calculators?

Accepted Answer

Most accurate with 1-6 reps (within 5%). Accuracy decreases above 10 reps. The Epley and Brzycki formulas are considered most reliable for low rep ranges. For best results, use a recent set of 3-5 reps.

Question 3

Should I test my actual 1RM?

Accepted Answer

Testing a true 1RM carries injury risk and requires a spotter, proper warm-up, and experience. Estimated 1RM from submaximal sets is safer and provides a reliable training benchmark — most coaches recommend this approach.

Question 4

How do I use my 1RM for training?

Accepted Answer

Strength training: 85-95% for 1-5 reps. Hypertrophy: 65-80% for 8-12 reps. Endurance: 50-65% for 15-20 reps. Most programs prescribe weights as percentages of your estimated 1RM.

Question 5

Why do different formulas give different results?

Accepted Answer

Each formula uses a different mathematical model. Epley and Brzycki work best for low reps (1-10). Mayhew works better for higher reps (10-15). The average of multiple formulas gives the most reliable estimate.

% of 1RM	Weight (lbs)	Est. Reps	Training Zone
100%	156	1	💪 Max Strength
95%	148	2	💪 Max Strength
90%	140	3-4	💪 Max Strength
85%	133	5-6	🏋️ Strength
80%	125	7-8	🏋️ Strength
75%	117	9-10	📈 Hypertrophy
70%	109	11-12	📈 Hypertrophy
65%	101	13-15	📈 Hypertrophy
60%	94	16-20	🔄 Endurance

One Rep Max (1RM) Calculator

🏋️ Select Exercise

📊 Formula Comparison

📋 Training Percentages

Frequently Asked Questions