Your one rep max is the single most important number in strength training. The bench press 1RM calculator gives you that figure without the risk of actually maxing out. Instead of grinding through dangerous heavy singles, enter any submaximal set and let the bench press 1RM calculator do the math.
ONE REP MAX TOOL
Bench Press 1RM Calculator
Use this bench press 1RM calculator to estimate the maximum weight you can lift for a single repetition. Enter a submaximal set and get your true one rep max instantly.
Enter your weight and reps to see your estimated 1RM
Training Percentages
Use your estimated 1RM to determine training loads for different goals
Calculate your 1RM first to see your training percentages
Where Do You Stand?
See how your bench press compares to strength standards for your bodyweight class
Why Use a Bench Press 1RM Calculator?
Avoid Max-Out Injuries
Get an accurate 1RM estimate without the joint stress, muscle tears, or spotter dependency of a true max attempt.
Program Percentages
Every serious strength program prescribes loads as a percentage of your 1RM. This calculator gives you the base number.
Benchmark Progress
Track your estimated 1RM over weeks and months to see if your programming is moving the needle.
How the Bench Press 1RM Works Calculator
Estimating your one rep max takes under 30 seconds:
- Warm up thoroughly with progressively heavier sets.
- Perform one set at a challenging weight — aim for 3 to 8 reps to failure.
- Enter the weight and reps into the bench press 1RM calculator above.
- Read your estimated one rep max from the results panel.
Tip: Sets of 3–6 reps produce the most accurate 1RM estimates. The further you go beyond 10 reps, the more fatigue skews the prediction.
Calculator Formulas
This bench press 1RM calculator uses five scientifically validated formulas — Epley, Brzycki, Lander, Lombardi, and O'Conner — then averages them for the most reliable estimate possible:
1RM = w × (1 + r / 30)
Epley Formula
1RM = w × (1 + r / 30)
The most widely used formula in strength training, developed by Boyd Epley. Simple, effective, and accurate for most rep ranges.
Brzycki Formula
1RM = w × (36 / (37 - r))
Created by Matt Brzycki. Particularly accurate for rep ranges of 1 to 10 and commonly used in academic strength research.
Lander Formula
1RM = (100 × w) / (101.3 - 2.67123 × r)
Derived from regression analysis of actual 1RM tests. Good balance of accuracy across different rep ranges.
Lombardi Formula
1RM = w × r0.10
Uses an exponential approach. Gives slightly different results at higher rep ranges, useful for cross-referencing your estimate.
O'Conner Formula
1RM = w × (1 + 0.025 × r)
A straightforward linear model. Quick to compute and provides reasonable estimates across most common rep ranges.
Training Chart
Once you have your 1RM, use the chart below to find exact training weights. For pure strength, work at 85–95%. For hypertrophy, stick to 65–80%. For muscular endurance, use 50–65%.
lbs
Strength
95%--1-2 reps
90%--2-3 reps
85%--3-5 reps
Hypertrophy
80%--4-6 reps
75%--6-8 reps
70%--8-10 reps
Endurance
65%--10-12 reps
60%--12-15 reps
50%--15-20 reps
Frequently Asked Questions
Common questions about bench press 1rm calculator
A bench press 1RM (one rep max) is the maximum amount of weight you can bench press for exactly one full repetition with proper form. It is the gold standard measure of upper body pressing strength.
When using a set of 3–8 reps, the bench press 1RM calculator is typically accurate within 5% of your true max. Accuracy decreases with higher rep ranges because fatigue and form breakdown introduce more variables.
Re-estimate your 1RM every 4–8 weeks. This gives enough time for meaningful strength adaptations while keeping your training data current. There is no need to test more frequently.
A true 1RM attempt carries higher injury risk than submaximal training. You should always have a competent spotter, use a power rack with safety pins, and only attempt a true max when fully recovered and properly warmed up.
Each formula uses a different mathematical model to estimate your max. Epley uses a linear relationship, Brzycki uses a ratio approach, and Lombardi uses an exponential model. The average of all five gives the most balanced estimate.
Sets of 3–6 reps are ideal. At these rep ranges, technique stays consistent and fatigue is manageable, giving all five formulas their best chance at an accurate prediction.
Yes, absolutely. Beginners benefit the most because they can establish a baseline 1RM without the risk of maxing out. As a beginner, use sets of 5–8 reps for your estimate and retest monthly to track your rapid early gains.