Bench Press Calculator

Your one-rep max (1RM) is the maximum amount of weight you can lift for a single repetition of an exercise with proper form. It's the gold standard for measuring absolute strength and is commonly used to program training loads as a percentage of your 1RM.

The calculator uses the Epley formula: 1RM = Weight × (1 + Reps / 30). You enter the weight you lifted and how many reps you completed, and the formula estimates the maximum weight you could lift for a single rep. The result is an estimate — actual performance can vary based on fatigue, technique, and other factors.

Testing a true 1RM carries an elevated injury risk, especially for beginners. Using a submaximal lift — for example, a weight you can lift for 3–10 reps — and plugging it into this calculator is a safer way to estimate your 1RM. Always have a spotter if you do attempt a true max effort.

The Epley formula is most accurate when you use a weight you can lift for 1–10 reps. Using more than 10 reps tends to reduce accuracy because muscular endurance becomes a larger factor. For best results, use a challenging set where you reached near-failure between 3 and 8 reps.

This calculator uses the Epley formula: 1RM = Weight × (1 + Reps ÷ 30). This is one of the most widely used and validated 1RM prediction formulas in exercise science. For a 1-rep input, it simply returns the weight itself as the 1RM.

Training percentages express a target weight as a fraction of your 1RM. For example, 80% of 1RM is typically used for hypertrophy training (6–8 reps), while 90%+ is used for maximal strength work (1–3 reps). These percentages help you select appropriate weights for each phase of your training program.

No — your 1RM is specific to each lift. Your bench press 1RM will be very different from your squat or deadlift 1RM because each exercise recruits different muscle groups and movement patterns. Always calculate 1RM separately for each exercise you want to program.

Yes. Select 'Kilograms (kg)' from the unit options before entering your weight. All results — including your estimated 1RM and training percentages — will be displayed in kilograms.