1 Rep Max Calculator
Estimate your one-rep max from a weight you lifted for reps, get a percentage-based training-load table, and see where your lift sits from Beginner to Elite.
Optional — needed to rate your level.
What is a 1 rep max?
Your one-rep max (1RM) is the most weight you can lift once with clean form. It anchors strength programming: most training loads are set as a percentage of it, so knowing it — even estimated — lets you pick weights that match the goal of each session.
How this 1RM calculator works
Enter a weight and the reps you completed with it, and the calculator estimates your 1RM using three established formulas, then averages them. Averaging keeps any single formula's bias from dominating, which matters most in the higher-rep ranges where estimates naturally spread.
Epley vs Brzycki vs Lombardi
Epley (weight × (1 + reps/30)) is the classic and tends to read slightly high; Brzycki (weight × 36/(37−reps)) tracks well up to about 10 reps and breaks down near 37; Lombardi (weight × reps^0.10) is a simple power curve. Each is most reliable at low reps — the fewer reps, the closer the estimate to a true max.
How to use 1RM percentages in training
The load table walks from 100% down to 50% of your estimated max with the rough reps expected at each. Strength blocks live around 80–95%, hypertrophy around 65–80%, and technique or speed work lower. Use them as starting points and adjust to how the bar actually moves.
Why an estimated 1RM isn't a true max
A rep-based estimate is a model, not a tested lift — fatigue, technique, and how close you were to failure all shift the number. If you want a real 1RM, build up to it over warm-up singles with a spotter or safeties, not off a calculator alone.
Turn your 1RM into a training plan
A number is only useful if it drives your training. GetMyCoach uses your strength and goal to build a structured plan with progression and recovery — so your percentages climb week to week instead of staying a one-off calculation.
Frequently asked questions
- How accurate is a 1 rep max calculator?
- Estimates are most accurate at low reps (1–5) and spread as reps rise. Averaging three formulas keeps the number sensible, but treat it as a close estimate, not a tested max.
- How many reps should I use for the best estimate?
- Use a set taken close to failure at 3–6 reps. Fewer reps means less extrapolation and a tighter estimate.
- Should I actually test my 1 rep max?
- Only with experience, a proper warm-up, and a spotter or safety bars. For most training you can program off the estimate and never need to max out.
- What is a good 1RM for my lift?
- It depends on your bodyweight and sex. Add both above and this tool rates the main barbell lifts from Beginner to Elite against population standards.
Build a strength plan around your numbers
Use your estimated 1RM to create a structured strength plan with progression, recovery and sport-specific training loads.