One-rep max calculator
Enter a weight you've lifted and how many reps you managed. We'll estimate your one-rep max (1RM) and turn it into training weights — no need to actually max out.
Your estimated one-rep max
75 kg
The all-rounder. Most accurate for sets under 10 reps.
Training weights by percentage
| % of 1RM | Weight | Reps | Best for |
|---|---|---|---|
| 95% | 72.5 kg | 1–2 | Peaking |
| 90% | 67.5 kg | 2–3 | Heavy strength |
| 85% | 65 kg | 4–6 | Strength |
| 80% | 60 kg | 6–8 | Strength & muscle |
| 75% | 57.5 kg | 8–10 | Muscle building |
| 70% | 52.5 kg | 10–12 | Muscle building |
| 65% | 50 kg | 12–15 | Muscle endurance |
| 60% | 45 kg | 15+ | Technique & endurance |
Warm-up ramp for 60 kg
Work up to your working weight gradually — never jump straight to it cold.
- Set 120 kg × 10 reps
- Set 230 kg × 8 reps
- Set 342.5 kg × 5 reps
- Set 450 kg × 2 reps
- Working sets60 kg
What is a one-rep max?
Your one-rep max (1RM) is the heaviest weight you can lift once with good form. It's the benchmark strength coaches use to set training weights: a programme might call for "5 reps at 80% of your 1RM". Testing a true max is tiring and carries injury risk, so most people estimate it from a lighter set — which is exactly what this calculator does.
How accurate is a 1RM estimate?
Estimates from sets of 5 reps or fewer are usually within a few percent of your true max. Beyond 10 reps the guess gets looser, because endurance starts to matter more than pure strength. That's why this calculator caps at 20 reps and lets you compare formulas — if Epley, Brzycki and Lombardi all land close together, you can trust the number.
How to use your 1RM in training
For building strength, most of your working sets sit between 75% and 90% of your 1RM. For building muscle, 65% to 85% with higher reps works well. Re-test or re-estimate every 4 to 6 weeks — as you get stronger, your training weights should move up with you. Or let your Gyde do it: it estimates your max from every set you log and moves your weights on automatically.
Common questions
Should I ever test my true 1RM?
If you're new to lifting, no — the injury risk isn't worth it, and an estimate is plenty. Experienced lifters sometimes test before a competition or a new training block, always with a spotter and a proper warm-up.
Why do the formulas give different answers?
Each formula was built from different groups of lifters. They agree closely on low-rep sets and drift apart on high-rep sets. Pick one and stick with it — consistency matters more than which one you choose.
Does my 1RM differ between exercises?
Yes, completely. Your squat, bench press and deadlift each have their own max. Estimate each lift separately from a set of that lift.
How often should I recalculate?
Every 4 to 6 weeks, or whenever your working weights start feeling noticeably easier. Strength moves fastest in your first year of training.
Working with a barbell? Use our barbell plate calculator to see exactly which plates to load, or estimate your daily calories with the TDEE calculator.
Your Gyde tracks every lift, sets your working weights and moves them on session by session. No gym maths needed.
Try 7 days free