What is 1RM (One Rep Max)?

1RM or One Rep Max is the maximum weight you can lift for a single rep with proper form. It's the most accurate strength benchmark in weightlifting. Example: if you bench press 80 kg for 5 reps, your 1RM is about 93 kg.

How do I calculate 1RM without lifting my max weight?

Use the Epley formula: 1RM = Weight × (1 + 0.0333 × Reps). Just lift your usual weight for 5-8 reps, enter the weight and reps into the calculator, and we'll estimate your 1RM. No need to risk injury by lifting your max weight.

What is the Epley formula and how accurate is it?

Epley formula: 1RM = Weight × (1 + 0.0333 × Reps). This formula is scientifically validated and is the industry standard in fitness. It's highly accurate for reps under 10. The fewer reps you use as a reference, the more accurate your 1RM estimate.

What percentage of 1RM is ideal for hypertrophy?

For hypertrophy (muscle growth), the ideal target is 67-85% of your 1RM, with a rep range of 6-12 per set. This is the most effective training zone for building muscle size. Max strength at 90%+ (1-5 reps), and endurance at 60% and below (15+ reps).

Is it safe to test my 1RM directly?

Testing your 1RM directly carries injury risk, especially if you're new or training alone. Always use a spotter for bench press, and don't push yourself if your body gives warning signals. That's why this 1RM calculator is safer — just lift light-to-moderate weight, we estimate the rest.

1RM

Fitness Tool

1RM Calculator

Calculate your One Rep Max instantly. Just enter the weight and reps you lifted — let this calculator do the rest.

Uses Epley formula Real-time results Free, no sign-up needed

Enter Your Lift Details

Weight Lifted (kg)

Number of Reps

Enter 1-30 reps. The more reps, the more accurate your 1RM estimate.

Your Estimated 1RM

Based on 80 kg × 5 reps

⚡ You can lift this weight — 93.3 kg — if you go for a one rep max effort.

What Is 1RM?

1RM (One Rep Max) is the maximum weight you can lift for one single rep with proper form. Simply put, it's your strength limit — how heavy a weight you can push, pull, or lift just once.

For example, if you bench press 80 kg for 5 reps — your 1RM isn't 80 kg, it's more than that (about 93 kg). Because if you try lifting 80 kg for just 1 rep, it's too light to measure your maximum strength.

But never try lifting your max weight alone without a spotter, especially if you're new. You could get injured. That's why this 1RM calculator is useful — just lift your usual weight, and we'll estimate your 1RM without you having to attempt a weight that makes you fail.

Why 1RM Matters For You

→ Progressive Overload — So you know when it's time to increase weight. If your 1RM goes up, you're getting stronger.
→ Training Zone Determination — Want to train for strength (low reps), hypertrophy (medium reps), or endurance (high reps)? Your 1RM is your guide.
→ Progress Tracking — With G-Trackt, you can log all your lifts and see your 1RM graphs go up week by week.

The formula used in this calculator is the Epley Formula, scientifically validated for estimating 1RM from sub-maximal lifts: 1RM = Weight × (1 + 0.0333 × Reps). No need to overthink it — just enter your numbers and you're done.

Tabel Persentase 1RM

Here's a reference table of 1RM percentages for various rep ranges. Use this table to determine the right weight — just check your 1RM, multiply by the percentage, done.

% 1RM	Rep Range	Weight to Use	Intensity

* These are estimates based on the Epley formula. Your actual results may vary depending on technique, fatigue level, and exercise type.

Log All Your Lifts on G-Trackt

G-Trackt isn't just a 1RM calculator. You can log workouts, track hypertrophy progress, count calories, use a fasting timer, and monitor body metrics — all free.

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1RM Calculator

Enter Your Lift Details

What Is 1RM?

Why 1RM Matters For You

Tabel Persentase 1RM

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