Calculator inputs
Use a recent close grip bench set. The calculator can blend several formulas or follow one specific method.
RPE adjustment uses a simple reps in reserve estimate: effective reps = performed reps + (10 - RPE). This is an approximation, not a competition result.
Example data table
| Sample weight | Reps | RPE | Effective reps | Average estimated 1RM | Training max |
|---|---|---|---|---|---|
| 70 kg | 8 | 9 | 9 | 89.5 kg | 80.5 kg |
| 80 kg | 5 | 9 | 6 | 95.5 kg | 86.0 kg |
| 90 kg | 3 | 10 | 3 | 99.5 kg | 89.5 kg |
| 225 lb | 6 | 8.5 | 7.5 | 275 lb | 247.5 lb |
Formula used
This calculator compares several established one-rep max equations and can also average them for a more balanced estimate.
RPE-adjusted reps
Effective reps = performed reps + (10 − RPE)
Epley: 1RM = weight × (1 + effective reps ÷ 30)
Brzycki: 1RM = weight × 36 ÷ (37 − effective reps)
Lander: 1RM = 100 × weight ÷ (101.3 − 2.67123 × effective reps)
Lombardi: 1RM = weight × effective reps0.10
O'Conner: 1RM = weight × (1 + 0.025 × effective reps)
Mayhew: 1RM = 100 × weight ÷ (52.2 + 41.9 × e-0.055 × effective reps)
Wathan: 1RM = 100 × weight ÷ (48.8 + 53.8 × e-0.075 × effective reps)
Training max is set to 90% of the selected 1RM estimate. Percentage loads are then derived from that estimated maximum.
How to use this calculator
- Enter the weight you used for a close grip bench set.
- Type the number of clean reps you completed.
- Select kilograms or pounds.
- Add bodyweight if you want a relative strength ratio.
- Choose the RPE that matches the effort of the set.
- Pick one formula or use the average option.
- Select your preferred plate rounding increment.
- Press the calculate button to view results above the form.
- Use the percentage table for programming and export the report when needed.
Frequently asked questions
1. Is this calculator only for close grip bench press?
Yes. It is tuned for sets performed with a close grip bench variation. You can still test other pressing movements, but the output is best interpreted for close grip bench programming.
2. Why does the calculator show several formulas?
Different one-rep max equations respond differently to reps and fatigue. Showing several methods helps you compare estimates and pick a conservative or aggressive planning number.
3. What does the average option do?
The average option blends all valid formula outputs into one estimate. It is useful when you want a smoother planning number rather than relying on one equation alone.
4. How does RPE affect the result?
Lower RPE means you likely had reps left in reserve. The calculator converts that into effective reps, which raises the estimated one-rep max compared with an all-out set.
5. What rep range works best for one-rep max estimates?
Most formulas are strongest when your working set is between one and ten reps. Higher-rep sets can still be useful, but estimates may become less stable.
6. What is a training max?
A training max is a reduced planning number, commonly 90% of estimated one-rep max. It helps you program productive loads without treating every cycle like a max test.
7. Why add bodyweight?
Bodyweight allows the page to show a relative strength ratio. That ratio can help you compare progress over time, especially during weight gain or weight loss phases.
8. Should I use this instead of testing a real max?
Use it as a planning and tracking tool. A real max attempt is still the direct measure, but estimated maxes reduce fatigue and make progress monitoring safer and easier.