Calculate your estimated one rep max from any weight and rep combination. Get your full training percentage table and lift level instantly.
Weight Units
Choose pounds or kilograms
Weight Unit
Select Your Lift
Choose the exercise you are calculating for
Your Lift Details
Enter the weight you lifted and how many reps you completed
lbs
Athlete Details
Optional — used to assess your lift relative to body weight
lbs
Estimated One Rep Max
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lbs
0.0x
BW Ratio
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Lift Level
0
Wilks Score
Training Percentages and Rep Targets
One Rep Max vs Body Weight
1RM Across Different Formulas
Training Notes
Full Breakdown
What Is a One Rep Max?
Your one rep max (1RM) is the maximum amount of weight you can lift for a single repetition of any given exercise with proper form. It is the gold standard measure of strength in weightlifting and powerlifting and is used to structure training programs, track progress over time and compare strength levels between athletes. You do not need to actually attempt a true one rep max lift to know your number — you can estimate it accurately from any weight and rep combination using a validated formula.
Knowing your 1RM is important because most evidence based strength and hypertrophy programs are written as percentages of your one rep max. When a program says to lift at 75 percent for four sets of eight, that 75 percent is calculated from your 1RM. Without knowing your number it is impossible to follow a percentage based program correctly.
Most accurate inputs: Use a weight you can lift for 2 to 10 reps with good form and maximum effort. The closer your rep count is to 1 the more accurate the estimate. Above 15 reps the formulas become less reliable because factors like muscular endurance start to play a larger role than pure strength.
How to Use This Calculator
1
Select Your Lift
Choose the exercise you are calculating for. Select squat, bench press, deadlift, overhead press, barbell row or any other lift. The lift type is used to assess your level.
2
Enter Weight and Reps
Type in the weight you lifted and how many reps you completed. For best accuracy choose a weight you can move for 3 to 8 reps with maximum effort and solid form.
3
Get Your Full Results
See your estimated 1RM, a full training percentage table, lift level assessment, body weight ratio, Wilks score and comparison across four different calculation formulas.
One Rep Max Training Percentage Guide
Once you know your 1RM you can use the percentages below to structure your training. Different percentage ranges produce different training adaptations.
Percentage of 1RM
Rep Range
Training Goal
Example Use
90 to 100%
1 to 2 reps
Maximum strength
Peaking and competition prep
80 to 90%
2 to 4 reps
Strength development
Heavy strength work and PRs
70 to 80%
4 to 6 reps
Strength and size
Main working sets in powerbuilding
60 to 70%
8 to 12 reps
Hypertrophy (muscle growth)
Bodybuilding accessory work
50 to 60%
12 to 20 reps
Muscular endurance
Volume work and conditioning
Frequently Asked Questions
Research suggests the Epley and Brzycki formulas are the most accurate for most people in the 1 to 10 rep range. The Lombardi formula tends to overestimate slightly while the Mayhew formula works well for higher rep ranges. No single formula is universally most accurate because individual differences in muscle fiber type, training experience and lift efficiency all affect how well any person converts sub-maximal effort to a true maximum. Using the average of multiple formulas as this calculator does gives a more reliable estimate than relying on any single one.
Attempting a true one rep max is not necessary or recommended for most people. The risks of injury are significantly higher when lifting at absolute maximum effort, especially without a spotter, proper warm-up and significant experience with the movement. For most lifters using the calculator to estimate 1RM from a submaximal set is safer, equally reliable and requires no recovery time. Competitive powerlifters and experienced strength athletes may attempt true maxes in a meet context but even they rarely do so in regular training.
For most people recalculating every 4 to 8 weeks is a good frequency. Beginners progress faster and may want to recalculate more often, sometimes every 2 to 4 weeks, as their strength can increase significantly in a short time. Intermediate and advanced lifters progress more slowly and 6 to 8 weeks is a more realistic testing window. You can also recalculate any time you complete a set that feels significantly easier than expected, which suggests your strength has improved since the last calculation.
The Wilks score is a formula developed by Robert Wilks that allows fair comparison of strength between lifters of different body weights and genders. It adjusts your total lifted weight based on your body weight using coefficients derived from elite powerlifting data. A higher Wilks score means you are stronger relative to your body weight. In powerlifting competitions the Wilks score is used to determine the best overall lifter regardless of weight class. For recreational lifters it is a useful way to compare your strength progress over time as your body weight changes.
Yes. The accuracy of 1RM estimation decreases as rep count increases. Between 2 and 10 reps the formulas are reasonably reliable with most studies showing estimates within 5 to 10 percent of actual 1RM. Between 10 and 15 reps the error increases as muscular endurance begins to play a larger role than raw strength in how many reps you can complete. Above 15 reps the estimates become significantly less reliable. For the most accurate estimate use a weight you can lift for 3 to 6 reps with maximum effort.
Strength standards vary by body weight, gender and training experience. As general benchmarks for an adult male, a body weight squat is a beginner standard, a 1.5 times body weight squat indicates intermediate level, and a 2 times body weight squat is considered advanced. For bench press, 0.75 times body weight is beginner, 1.25 times is intermediate and 1.75 times is advanced. Deadlift standards are typically slightly higher than squat. For females the standards are roughly 20 to 30 percent lower in absolute terms but comparable when expressed as a body weight ratio.
Once you know your 1RM you can use the training percentage table this calculator produces to set your working weights for any program. For example if a program calls for 5 sets of 5 at 80 percent of your 1RM and your 1RM is 300 lbs, you would work at 240 lbs. Most popular strength programs including 5/3/1, GZCLP and Juggernaut are built around 1RM percentages. Update your 1RM regularly and adjust your working weights accordingly to ensure you are always training at the right intensity for your current strength level.
