1RM Calculator
Enter the weight you lifted and how many reps you performed (1–12) to instantly see your estimated one-rep max and a full training percentage breakdown.
Epley's formula is 1RM = weight × (1 + reps ÷ 30), so 225 lb for 5 reps estimates a 262.5 lb max.
Use the 1RM Calculator
Lift Details
Enter a weight and rep count, then click Calculate.
Supports 1–12 reps using 5 validated formulas.
Average 1RM
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lb
Formula Breakdown
| Formula | Est. 1RM |
|---|
Training Percentage Table
| % of 1RM | Weight |
|---|
Quick answer
Epley's formula is 1RM = weight × (1 + reps ÷ 30), so 225 lb for 5 reps estimates a 262.5 lb max. The five formulas here give 253 to 264 lb for that set and average 257.8 lb. Estimates get less reliable as the rep count goes up.
Examples
| Set | Epley | Brzycki | Average of 5 |
|---|---|---|---|
| 225 lb × 5 | 262.5 | 253.1 | 257.8 |
| 315 lb × 3 | 346.5 | 333.5 | 341.6 |
| 135 lb × 10 | 180.0 | 180.0 | 175.9 |
| 100 kg × 8 | 126.7 | 124.1 | 123.8 |
Enter your weight and reps.
Summary
Enter the weight you lifted and how many reps you performed (1–12) to instantly see your estimated one-rep max and a full training percentage breakdown.
How it works
- Enter the weight you lifted in the Weight field.
- Select your unit — pounds (lb) or kilograms (kg).
- Enter the number of reps you performed (1 through 12).
- Choose a specific formula or leave it on "Average all 5" for a consensus estimate.
- Click Calculate to see your estimated 1RM and the full training percentage table.
Use cases
- Determine your theoretical maximum lift for programming a strength cycle.
- Set target weights for each percentage zone in a powerlifting or Olympic lifting program.
- Track relative strength progress over time without maxing out every session.
- Compare your estimated 1RM across different formulas for a more confident number.