strength calculator
Get Started

One Rep Max
Calculator

Calculate your one-rep max (1RM) for any lift.
Your one-rep max is the max weight you can lift for a single repetition for a given exercise.

⚡ 1RM Calculator
—
lb
Estimated 1RM
Training Goal % of 1RM Weight
Reference Chart

Repetition Percentages of 1RM

Use this 1RM percentage chart to plan your training weights based on your one rep max.

RepetitionsPercentage of 1RM
Training Percentage Calculator

1RM Percentage Chart

Use this chart to program your training with precision. Shows the relationship between % of 1RM, expected reps, and training goal.

% of 1RM Expected Reps Training Zone Intensity
100%1Max Effort / True 1RM
95%1–2Competition Opener / Peaking
90%2–3Near-Max Strength / Singles
85%3–5Heavy Strength Work
80%5–6Strength / Power Development
75%6–8Moderate Strength / Size
70%8–10Hypertrophy / Muscle Growth
65%10–12Volume / Hypertrophy
60%12–15Light Volume / Endurance
50%15–20+Active Recovery / Warm-up
Step-by-Step

How To Use The 1RM Calculator

You don't need to risk a dangerous one-rep attempt. Here's how to find your 1RM in four simple steps.

01
Choose Your Lift

Select from bench press, back squat, deadlift, overhead press, power clean, or Pendlay row.

02
Enter Your Numbers

Input the weight you lifted and the number of reps completed. Best results with 1–10 reps near failure.

03
Get Your Estimated 1RM

Our calculator computes your one rep max using five proven formulas and averages them for peak accuracy.

04
Use Training Percentages

Scroll up to see your full 1RM percentage breakdown — from 50% warm-up weights to 95% competition openers.

Pro Tip

Best Rep Range for Accuracy: The calculator is most accurate with sets of 1–6 reps. Above 10 reps, muscular endurance factors increase prediction error. Use a recent heavy set of 3–5 reps for best results.

1RM Calculator FAQ

Frequently Asked Questions

Everything you need to know about one rep max, how the formulas work, and using the calculator for your strength training programming.

Your one rep max (1RM) is the maximum amount of weight you can lift for a single repetition with proper form. It's the gold standard for measuring absolute strength in powerlifting, weightlifting, and general strength training. Knowing your 1RM allows you to program training percentages, track progress, and benchmark your strength level.
Enter the weight you lifted and the number of reps completed into the calculator above. Our tool applies five validated formulas (Epley, Brzycki, Lander, O'Conner, Lombardi) and averages the results to produce your estimated 1RM. For best accuracy, use a set of 1–6 reps performed near failure.
Use this calculator with any recent submaximal set — ideally 3–5 reps at near-failure. The estimated 1RM (e1RM) approach avoids the injury risk of a true max attempt while delivering ±3–5% accuracy. You can recalculate weekly as your training weights progress without ever risking a maximal single.
No single formula is universally best — Brzycki excels at low reps, Lombardi handles higher reps better, and Epley is the most widely validated overall. That's why our calculator averages all five: Epley, Brzycki, Lander, O'Conner, and Lombardi. The average consistently outperforms any single formula across different rep ranges.
When using sets of 1–6 reps, multi-formula e1RM calculators are accurate to within ±3–5% of true 1RM according to peer-reviewed research. Accuracy declines above 10 reps as muscular endurance factors increase variance. Our five-formula averaging approach minimizes individual formula error for the most reliable estimate possible.
You can recalculate your e1RM after every training session where you set a new weight or rep record. Because you're using submaximal effort, there's no recovery cost. Most lifters update their e1RM weekly or at the end of each training block to keep programming percentages current.
Training percentages express working weight as a fraction of your 1RM. For example, 80% of a 200 lb 1RM is 160 lbs. These percentages correspond to specific rep ranges and training goals: 85–95% builds maximum strength, 70–80% develops strength and size, and 60–70% is used for hypertrophy and volume work.