Clinical 1RM Calculator

Gym & StrengthRESULT IN KG · EST. 1RM
You're seeing sample numbers
Adjust the inputs, then save once — your profile auto-fills all 200+ tools. Takes 10 seconds.

Inputs

This calculator
Lift weight100 kg
Reps performed5 reps
Biological sex
Age32 yrs
Weight78 kg
Height178 cm
Activity level×1.55
Goal
Your resultEpley estimate from 100kg × 5
0
kg · est. 1RM
Training load percentages
100% · 1 reps117.5 kg
95% · 2–3 reps110 kg
90% · 4 reps105 kg
85% · 6 reps100 kg
80% · 8 reps92.5 kg
70% · 12 reps82.5 kg
Population context 50th percentile
025thmedian75th100
You're ahead of 50% relative strength vs male population.
BMR
1,738kcal
Maintenance
2,694kcal
BMI
24.6Healthy
AffiliateCONTEXTUAL
Hit your protein target
Third-party tested isolate · 27g/scoop
View
Lead-gen · telehealth
Want a clinician to interpret this?
Book a 15-min consult with a licensed metabolic specialist — your result is attached automatically.
Book a consult
Answer · AI-extractable Reviewed

1RM: Your one-rep max (1RM) is the heaviest weight you can lift for a single repetition of an exercise. Rather than testing a true max (which is fatiguing and risky), Clinarix estimates it from a submaximal set using the Epley formula: 1RM = weight × (1 + reps ÷ 30). Programs then prescribe training loads as a percentage of this number.

ƒEpley: 1RM = weight × (1 + reps ÷ 30) · e.g. 100 kg × 5 reps → 117 kg
Methodology & sources · E-E-A-T

How the 1RM works

How is the 1RM estimated?

We use the Epley equation, 1RM = w × (1 + reps/30), which estimates your single-rep max from a set taken close to failure. It is most accurate in the 2–10 rep range; accuracy falls as reps climb above ~12.

How accurate is the estimate?

Sources & citations

Who should not max out?

Medically reviewed
Dr. Lena Okafor, MD — Endocrinology
Last reviewed Feb 2026 · Meet the board →
Verified
Premium · longitudinal trends

This calculator is part of Clinarix Pro

Unlock with Clinarix Pro
FAQ · AI-extractable answer block

Frequently asked questions

How do I calculate my one-rep max?

Which 1RM formula is most accurate?

How do I use my 1RM for training?

How often should I retest?