What your estimated 1RM means
Your estimated one-rep max (1RM) is the maximum weight you could theoretically lift for one repetition, based on a set you have already completed. Instead of testing a true maximum, you can use a set of multiple reps to estimate your bench press max.
The result is an estimate, not a measured maximum. Your actual 1RM can vary depending on technique, fatigue, experience, and how close the completed set was to failure.
How to calculate bench press 1RM
This calculator uses the Epley formula for sets of two or more reps:
1RM = weight × (1 + reps ÷ 30) For example, if you bench press 100 kg for 5 reps:
100 × (1 + 5 ÷ 30) = 116.7 kg So your estimated bench press 1RM is 116.7 kg. If you enter 1 rep, the calculator treats the weight you actually lifted as your 1RM rather than applying the formula to a single.
If you're looking for a general calculation rather than a bench-specific estimate, you can also use our One-Rep Max Calculator.
Bench press 1RM percentages
Once you know your estimated 1RM, you can use percentages of it to choose training weights. For a 116.7 kg estimated max:
| Percentage | Weight |
|---|---|
| 95% | 110.8 kg |
| 90% | 105.0 kg |
| 85% | 99.2 kg |
| 80% | 93.3 kg |
| 75% | 87.5 kg |
The calculator works these percentages from the exact 1RM before rounding the displayed weight. This avoids small rounding differences between the main result and the percentage table.
How accurate is a bench press 1RM estimate?
A 1RM formula gives you a useful estimate, but it cannot reproduce your exact maximum for every lifter. The accuracy depends mainly on the number of reps, how close the set was to failure, and your individual strength profile.
- Rep count. Lower-rep sets generally require less extrapolation. As the number of reps increases, endurance contributes more to the result and the estimate can become less reliable.
- Distance from failure. The estimate assumes the set was challenging. If you stopped with several reps still available, the calculated 1RM may underestimate your actual maximum.
- Individual variation. Lifters differ in how many reps they can perform at a given percentage of their maximum, so the same weight and rep count can produce different real-world results.
For that reason, use an estimated 1RM as a training reference rather than as a guaranteed maximum. If you test a true 1RM, use appropriate safety equipment and a spotter.
Why estimate your bench press max?
You don't need to attempt a maximum single every time you want to track your strength. Estimating your 1RM from a normal working set lets you compare your strength over time without performing a maximal lift.
For example, if you previously lifted 100 kg for 5 reps and later manage 105 kg for 5 reps, the estimated 1RM rises from 116.7 kg to 122.5 kg. The change gives you a simple way to track progress from your regular training sets.
Using kg or lb
The formula works the same way in kilograms and pounds. Enter the total weight you lifted and select the appropriate unit. For example, 225 lb for 5 reps gives an estimated 1RM of 262.5 lb.
If you need to convert between kilograms and pounds, use our Weight Converter.
Frequently asked questions
How do I calculate my bench press 1RM?
For two or more reps, multiply the weight you lifted by (1 + reps ÷ 30). For example, 100 kg × 5 reps gives 100 × (1 + 5 ÷ 30) = 116.7 kg. The calculator above performs the calculation for you.
What is my bench press max if I only did one rep?
If you completed one rep, the weight you lifted is your actual one-rep max for that lift. The calculator therefore returns the weight unchanged instead of applying the Epley formula.
How many reps should I use to estimate my bench press 1RM?
Lower-rep sets generally give a more direct estimate because there is less extrapolation. A challenging set of a few reps is commonly used, while higher-rep sets can be less reliable.
Should I include the bar's weight?
Yes. Enter the total weight you lifted, including the bar and plates. For example, if the bar weighs 20 kg and you loaded 80 kg of plates, enter 100 kg.
Does the bench press 1RM formula work in pounds?
Yes. The same formula works with pounds or kilograms. The important thing is to use one unit consistently for the weight and the resulting 1RM.