One Rep Max Calculator
Estimate your one-rep max (1RM) using multiple proven formulas. Enter the weight lifted and number of reps performed.
Estimated 1RM (Average)
258.3 lbs
Epley
262.5
Brzycki
253.1
Lombardi
264.3
O'Conner
253.1
Training Load Table
1 rep (100%)
258.3 lbs
2 reps (95%)
245.3 lbs
3 reps (93%)
240.2 lbs
4 reps (90%)
232.4 lbs
5 reps (87%)
224.7 lbs
6 reps (85%)
219.5 lbs
8 reps (80%)
206.6 lbs
10 reps (75%)
193.7 lbs
12 reps (70%)
180.8 lbs
15 reps (65%)
167.9 lbs
20 reps (60%)
155.0 lbs
How 1RM Estimation Works
One-rep max (1RM) estimation formulas use the weight you lift and the number of repetitions to estimate the maximum weight you could lift for a single rep. These are most accurate for 2-10 reps; higher rep ranges reduce accuracy.
Features
- 4 estimation formulas (Epley, Brzycki, Lombardi, O'Conner)
- Rep percentage table for programming
- Supports lbs and kg
- Average across all formulas
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Disclaimer: This tool is provided as-is for informational and educational purposes only.