Strength Calculator

The Strength Calculator helps you estimate your one-rep max (1RM) for any major lift — like bench press, squat, deadlift, or overhead press — based on the weight you lifted and how many reps you performed. It also suggests training percentages for strength, hypertrophy, or endurance goals.

How to Use the Strength Calculator

To use this tool, enter:

• The weight you lifted
• The number of reps you completed
• Select your preferred 1RM formula (Epley, Brzycki, Lombardi, etc.)

The calculator will show your estimated 1RM and suggested training loads (percentages) for different goals.

Strength Calculator Formulas

Example (Epley Formula):

1RM = Weight × (1 + Reps ÷ 30)

Other options include Brzycki, Lombardi, O’Conner — useful for different rep ranges.

Example

If you lift 100 kg for 5 reps using Epley:
→ 1RM = 100 × (1 + 5 ÷ 30) = 116.7 kg
→ Strength sets (85%): ~99 kg
→ Hypertrophy sets (70%–80%): 82–93 kg

Common Use Cases

• Powerlifting and strength programming
• Planning progressive overload cycles
• Tracking lifting progress over time
• Setting safe training loads
• Testing performance without maxing out

Why Use a Strength Calculator?

Testing true 1RM can be risky and fatiguing. This tool estimates it safely, so you can plan your workouts precisely, stay injury-free, and make consistent gains.

Frequently Asked Questions (FAQs)

Which formula is best?

Epley is reliable for 1–10 reps. Brzycki works well for 5–10 reps. Use multiple for comparison.

Is 1RM testing safe for beginners?

It’s better for beginners to estimate 1RM than max out. Test under supervision only.

Does this work for any lift?

Yes — bench, squat, deadlift, press, curls — any resistance movement.

How do I use the percentages?

Train at 80–90% for strength, 70–80% for hypertrophy, 50–70% for endurance or deload weeks.

Should I retest my 1RM?

Yes, update your 1RM every 6–12 weeks to adjust your program as you progress.

Related tools: 1RM Calculator, Squat Calculator, Gain Calculator.