1RM Calculator

How to calculate one rep max?

The most common method is the Epley formula: 1RM = Weight x (1 + Reps/30). For example, if you bench press 100 kg for 5 reps, your estimated 1RM is 100 x (1 + 5/30) = 116.67 kg. This calculator uses 7 different formulas and averages them for a more accurate estimate. For safety, use a weight you can lift 3-8 times with good form.

What is a good one rep max for bench press?

One rep max standards vary by bodyweight and training experience. General benchmarks for males: Beginner (0.5x bodyweight), Intermediate (1x bodyweight), Advanced (1.5x bodyweight), Elite (2x bodyweight). For females, multiply these by approximately 0.6. For example, a 80 kg intermediate male lifter would target around 80 kg bench press 1RM.

What percentage of 1RM should I lift for muscle growth?

For hypertrophy (muscle growth), most research recommends training at 65-80% of your 1RM for 8-12 reps per set. For example, if your 1RM bench press is 100 kg, train with 65-80 kg for sets of 8-12. Progressive overload — gradually increasing weight or reps over time — is the key driver of muscle growth.

How accurate is a 1RM calculator?

One-rep max calculators are most accurate when using data from 1-10 reps. Accuracy decreases significantly above 10 reps because muscular endurance becomes a larger factor. The Epley and Brzycki formulas are considered the most reliable, typically within 5% of your actual 1RM. For the most accurate result, use a weight you can lift 3-5 times.

Epley vs Brzycki formula: which is more accurate?

Both are widely used and considered accurate. The Brzycki formula tends to give slightly lower estimates and is considered more accurate for 1-7 reps. The Epley formula works well for 2-10 reps. Neither is definitively "better" — this calculator shows both plus 5 additional formulas so you can compare and use the average for the best estimate.

How often should I test my one rep max?

Most coaches recommend testing your actual 1RM every 8-12 weeks, as frequent maximal testing increases injury risk and fatigue. Between tests, use this calculator with submaximal lifts (3-5 reps) to estimate your progress. Always warm up thoroughly before attempting heavy singles, and use a spotter for safety.

How to increase your one rep max?

Focus on progressive overload by gradually increasing weight or reps over time. Train at 85-95% of your 1RM for 1-5 reps to build maximal strength. Ensure adequate recovery (48-72 hours between heavy sessions), eat sufficient protein (1.6-2.2 g/kg bodyweight), and get 7-9 hours of sleep. Accessory work targeting weak points (triceps for bench, glutes for squat) also helps.

Is it safe to attempt a one rep max?

Direct 1RM testing carries higher injury risk than submaximal training. It is safer for experienced lifters with good technique. Always use a spotter, warm up with progressive sets (50%, 70%, 85%, 95%), and never attempt a 1RM when fatigued. For beginners, using this calculator with 3-5 rep sets is a much safer alternative to direct testing.