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Health & Fitness · Free Calculator

One Rep Max
Calculator

Estimate your one rep max (1RM) from any weight and rep count. Uses Epley, Brzycki, and Lombardi formulas averaged for the best estimate. Includes a complete training load chart.

Your Estimated 1RM
Average of 3 proven formulas
1RM (Avg)
117 kg
In Pounds
258 lbs
Epley
117
Brzycki
116
Training Load Chart (% of 1RM)
% 1RMkglbsRepsTraining Zone
// Health · ShashaTools
One Rep Max
Weight Lifted 100 kg
5500
The weight you lifted (in kg).
Reps Completed 5
130
How many reps you completed with good form. Best accuracy: 3-10 reps.
// Results
Estimated 1RM
117
Epley Formula
117 kg (258 lbs)
Brzycki Formula
116 kg (256 lbs)
Lombardi Formula
117 kg (258 lbs)
Average (Best Est.)
117 kg (258 lbs)
Estimated 1RM: 117 kg from 100 kg x 5 reps
How to Use This Calculator
Estimate your one rep max without actually maxing out
Step 1 Enter Your Lift
1
Enter weight lifted
The weight you used for your set (in kg). This should be a weight you lifted with proper form for the rep count entered.
2
Enter reps completed
How many full reps you completed. Most accurate between 3-10 reps. Above 10, accuracy decreases. At 1 rep, your 1RM equals the weight.
3
Read your 1RM
The average of 3 formulas gives the best estimate. Epley and Brzycki are shown individually for comparison.
4
Use the training chart
The percentage chart shows training loads from 50-100% of your 1RM with recommended rep ranges and training zones (strength, hypertrophy, endurance).
💡 Sweet spot: Use a 5-rep max for the most accurate 1RM estimate. It is heavy enough to be meaningful but not so heavy that form breaks down.
Step 2 Train With It
1
Strength: 80-90% 1RM
3-5 reps per set. Heavy compound lifts. Full recovery (3-5 min between sets). This builds maximal strength.
2
Hypertrophy: 65-80% 1RM
8-12 reps per set. Moderate weight, controlled tempo. 60-90 sec rest. This builds muscle size.
3
Endurance: 50-65% 1RM
15-20+ reps per set. Lighter weight, shorter rest (30-60 sec). Builds muscular endurance and work capacity.
4
Recalculate regularly
Re-estimate every 4-8 weeks as you get stronger. Use your heaviest working set of the week as the input.
💡 Tip: Never attempt an actual 1RM without a spotter and proper warm-up. The calculator gives you all the information you need to program training loads without the injury risk of maxing out.
// Recommended Strength Tools

ℹ️ Affiliate disclosure: Some links are affiliate links.

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Wrist support for pressing movements.
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Lifting Straps
Grip support for heavy pulls and rows.
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Workout Journal
Track lifts, reps, and 1RM progress over time.
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Body Fat Calculator
Track body composition with training.
// Complete Guide — Updated 2026

One Rep Max:
The Complete Guide

Your one rep max (1RM) is the maximum weight you can lift for a single repetition with proper form. It is the foundation of percentage-based strength training programs. Knowing your 1RM lets you calculate exact training loads for strength, hypertrophy, and endurance. This guide covers the three main estimation formulas, how to use percentage charts, and training strategies.

The Formulas

// Epley (Most Common)
1RM = Weight × (1 + Reps ÷ 30)
100 kg × (1 + 5/30) = 100 × 1.167 = 117 kg
// Brzycki
1RM = Weight × 36 ÷ (37 − Reps)
100 × 36 / (37 - 5) = 3600 / 32 = 113 kg

1RM Benchmarks (Body Weight Multiples)

LevelBench PressSquatDeadlift
Beginner0.5x BW0.75x BW1x BW
Intermediate1x BW1.5x BW2x BW
Advanced1.5x BW2x BW2.5x BW
Elite2x BW2.5x BW3x BW

Real-World Scenarios

Scenario 1: Bench Press Programming. James benches 80 kg for 8 reps. Estimated 1RM: 101 kg. His training plan: Strength day: 85 kg x 5 (85%), Hypertrophy day: 70 kg x 10 (70%), Volume day: 60 kg x 15 (60%). He recalculates after each 4-week block. Use our Protein Intake Calculator for recovery nutrition.

Scenario 2: Squat Progression. Maria squats 60 kg for 5 reps. 1RM: 70 kg (1.17x her 60 kg body weight = intermediate level). To progress to advanced (2x BW = 120 kg), she follows a linear progression: add 2.5 kg per week to her working sets. In 12 weeks: 60 + 30 = 90 kg x 5, new 1RM estimate: 105 kg.

Scenario 3: Deadlift Plateau. David deadlifts 180 kg for 3 reps. 1RM: 191 kg. He has been stuck for 8 weeks. Solution: deload to 70% (134 kg) for 2 weeks, then rebuild with a different rep scheme (5x5 at 80% instead of 3x3 at 90%). Deloading resets fatigue and often leads to new PRs. Use our Calories Burned Calculator to ensure adequate fueling.

Scenario 4: Beginner Setting Weights. Priya is new to lifting and does not know what weight to use. She finds she can bench the bar (20 kg) for 15 reps. 1RM: 30 kg. Her training weights: 70% = 21 kg (bar + small plates), 80% = 24 kg. She starts here and adds 1-2.5 kg per week. Use our TDEE Calculator for nutrition to support her new training.

💡 Key insight: You do not need to test your actual 1RM to train effectively. In fact, regularly maxing out increases injury risk and accumulates unnecessary fatigue. Use this calculator with a 3-5 rep set every 4-8 weeks to estimate your 1RM, then train at calculated percentages. This is how competitive powerlifters and strength coaches program training.

Training Zones
90-100%Strength/Power
80-90%Strength
70-80%Hypertrophy
60-70%Endurance
50-60%Warm-up
// Frequently Asked Questions
Common Questions About One Rep Max
How do I calculate my one rep max? +
Epley: 1RM = Weight x (1 + Reps/30). 100 kg x 5 reps: 100 x 1.167 = 117 kg. Most accurate with 3-10 reps.
Which formula is most accurate? +
Epley and Brzycki are equally accurate for 1-10 reps. Brzycki tends slightly lower. Our calculator averages 3 formulas for best estimate.
How do I use the percentage chart? +
85-100% for strength (1-6 reps). 70-85% for hypertrophy (6-12 reps). 50-70% for endurance (12-20+ reps). Program your training from these.
Is it safe to test actual 1RM? +
Carries injury risk. Use a calculator instead. If testing: warm up thoroughly, use spotter, proper form, only attempt what you're confident you can lift.
How often should I test? +
Every 8-12 weeks or after a training block. Use the calculator weekly from working sets. Frequent actual max testing is unnecessary and fatiguing.
What percentage should I train at? +
Strength: 80-90% x 3-5 reps. Hypertrophy: 65-80% x 8-12 reps. Power: 50-65% x 3-5 explosive. Endurance: 50-65% x 15-20 reps.
Is 1RM different per exercise? +
Yes. Different 1RM for each lift. Deadlift typically highest, then squat, then bench. Calculate separately for each major movement.
How many reps for best estimate? +
3-10 reps is most accurate. Below 3, just test max. Above 10, accuracy drops. A 5-rep max is the sweet spot.
What is RPE? +
Rate of Perceived Exertion (1-10). RPE 10 = max (100% 1RM). RPE 8 = 2 reps left (~85%). RPE 7 = 3 left (~80%). Used in autoregulation training.
What are good 1RM benchmarks? +
Men: Bench 1x BW (intermediate), 1.5x (advanced). Squat 1.5x / 2x. Deadlift 2x / 2.5x. Women: roughly 60-70% of these multiples.