One Rep Max Calculator - Maximum Strength Assessment

Calculate your one repetition maximum using multiple validated formulas and optimize your strength training program.

Lift Details

20kg135kg250kg
1815
Upper Body

Calculation Method

Epley Formula

Simple and commonly used

1985

Brzycki Formula

Most popular and widely used

1993

Lombardi Formula

Good for higher rep ranges

1990

O'Conner Formula

Conservative estimate

1990

Wathan Formula

Most accurate for trained individuals

2006

Mayhew Formula

Excellent for powerlifting

2008

One Rep Max

116.7 kg

Epley Formula

Strength Level

Novice

Based on your performance

Tested With

100kg x 5

Bench Press

Repetition Maximum Table

RepsWeight% of 1RMIntensity
1113 kg96.8%Maximal
2109 kg93.8%High
3106 kg90.9%High
4103 kg88.2%Moderate
5100 kg85.7%Moderate
697 kg83.3%Moderate
892 kg78.9%Hypertrophy
1088 kg75%Hypertrophy
1283 kg71.4%Hypertrophy
1578 kg66.7%Endurance

Advanced Analysis

Formula Comparison

Training Zones

Strength

85-100%
1-5 reps • 3-5 sets

Maximal strength development

Power

75-85%
3-6 reps • 3-5 sets

Explosive power and speed

Hypertrophy

65-75%
6-12 reps • 3-4 sets

Muscle size and growth

Endurance

50-65%
12-20+ reps • 2-3 sets

Muscular endurance

Training Recommendations

Warm up properly before heavy attempts
Use spotters for maximal lifts
Focus on proper form over weight
Allow 48-72 hours recovery between max efforts

Are you looking to find your true strength potential? With the One Rep Max Calculator, you can estimate the maximum weight your muscles can lift for one repetition - the 1RM (One Repetition Maximum). Whether you are 'a powerlifter', 'a bodybuilder', or 'just working out to be healthy', knowing your one rep will help you design workouts, track progress, and avoid overtraining.

One Rep Max Calculator

What is a One Rep Max (1RM)?

A One Rep Max (1RM) is the heaviest weight you can lift for one full repetition while using proper technique. It is the gold standard to test muscular strength.

Our One Rep Max Calculator - (also known as a 1 rep max calculator or one rm calculator) helps you estimate this number safely - without having to test it directly in the gym.

By entering your weight lifted and the number of reps performed, the 1RM calculator instantly provides your estimated one rep max using multiple scientific formulas, including Epley, Brzycki, Lombardi, O'Conner, Wathan, and Mayhew.

How to use the One Rep Max Calculator

1.
Select your units:' - Choose between kilograms (kg) or pounds (lb).
2.
Enter the Weight Lifted:' - Place the weight you lifted.
3.
Add the number of Reps:' - Place the number of reps you did before failure.
4.
Choose your lift:' - The choice of the Bench Press, Squat, or Deadlift.
5.
Choose formula:' - Compare results from multiple formulas for higher accuracy.

The one rep max calculator then provides:

Your estimated 1RM value.
A strength level assessment (Beginner to Elite).
A repetition max table showing weights for 1-12 reps.
Training zones for strength, hypertrophy, and endurance.
An advanced analysis comparing multiple formulas.

Why use a One Rep Max Calculator?

It's important to know your one rep max to design effective training programs.

This tool is useful for the following reasons:

Intelligent Programming: - Determine percentages for 70%, 80%, or even 90% of you 1RM load for organized training sessions.
Avoid Overtraining: - Train safely without guessing your limits.
Track Progress: - See measurable improvements in strength over time.
Custom Workouts: - Adjust loads in hypertrophy, endurance or max strength training phases.
Science Based Accuracy: - The calculator uses established equations (Epley, Brzycki, etc.).

Our single rep max calculator simplifies the process so you can focus on performance - not math.

Understanding Training Zones

The One Rep Max Calculator also divides your training zones for better programming:

Endurance (50-65%) - High reps, low weight.
Hypertrophy (65-75%) - Muscle growth range.
Power (75-85%) - Strength and explosive performance.
Max Strength (85-100%) - Peak load for single lifts.

With this 1 rep calculator, you can tailor your training intensity precisely for your goals.

Supported Formulas in Our One RM Calculator

Our one rm calculator uses six proven methods:

1.
Epley Formula: - Best for moderate to high reps.
2.
Brzycki Formula: - Excellent for accurate low-rep estimates.
3.
Lombardi Formula: - Great for experienced lifters.
4.
O'Conner Formula: - Simplified for general fitness users.
5.
Wathan Formula: - High accuracy for advanced athletes.
6.
Mayhew Formula: - Common in strength and conditioning research.

Each formula provides a slightly different 1RM prediction, helping you cross-compare and find the most accurate estimate for your training style.

Key Features of the One Rep Max Calculator

Works for all major lifts - Bench Press, Squat, Deadlift, Overhead Press, etc.
Displays Repetition Maximum Table for 1-12 reps.
Shows Training Zone Distribution (Endurance, Hypertrophy, Strength).
Visual graph comparisons for formula accuracy.
Ideal for athletes, coaches, and fitness enthusiasts.

Whether you are just starting out or have an advanced level of fitness, the One Rep Max Calculator gives you the ability to lift more effectively, monitor your progression, and ultimately reach your top performance level. If you would like to track your progress and seek out your next training goal, measure your one rep max using the 1 rep max calculator, one rm calculator, or single rep max calculator.

FAQs

- Put simply, a One Rep Max Calculator estimates the heaviest weight you can lift for one rep, using formulas needing weight and rep count from your current training workouts. This is useful for programming your strength training within a safe range.

- The 1RM calculator is generally accurate if you enter in the correct values. Maxes tend to vary slightly based on experience, exercise, and level of fatigue (which is another variable), but most formulas should be within a few percent of actual maxes.

- Absolutely. Beginners can safely estimate their one rep max without performing risky heavy single lifts. It's perfect for setting progressive overload goals.

- The Epley formula is widely used and provides consistent results for most lifters. However, comparing results from multiple formulas (as our tool allows) gives the best accuracy.

- It is not a bad idea to test your 1 rm every six to eight weeks to keep up with strength progression.

- Yes! The One Rep Max Calculator on SantPro Tools is completely free, accurate, and optimized for desktop and mobile devices.