One Rep Max Calculator (KG)
Estimate your 1RM using multiple formulas and get training percentages
About the Formulas
Epley Formula
1RM = weight × (1 + reps/30)
Most commonly used, accurate for moderate rep ranges.
Brzycki Formula
1RM = weight × (36 / (37 - reps))
Popular in strength training, accurate for lower rep ranges.
Lombardi Formula
1RM = weight × reps^0.10
Simple exponential formula, good for general estimates.
O'Conner Formula
1RM = weight × (1 + 0.025 × reps)
Conservative estimate, tends to give lower values.