Strength
You almost never need to test a one-rep max. You can estimate it accurately enough from a set you were going to do anyway.
1RM is the heaviest weight you can lift once with good technique. You can estimate it from a hard set of 3–8 reps using weight × (1 + reps ÷ 30). Estimates are most accurate under about 6 reps and get unreliable past 10.
The Epley formula is the most commonly used: 1RM = weight × (1 + reps ÷ 30). Take a set close to failure — RPE 9 or so — and put the numbers in.
A set of 5 at 100 kg gives 100 × (1 + 5/30) = 117 kg.
| Reps at that weight | Percentage of 1RM | Multiply weight by |
|---|---|---|
| 1 | 100% | 1.00 |
| 2 | ~95% | 1.07 |
| 3 | ~93% | 1.10 |
| 5 | ~87% | 1.17 |
| 8 | ~80% | 1.27 |
| 10 | ~75% | 1.33 |
| 12 | ~70% | 1.40 |
Which is why the estimate is best used as your tracked number over time rather than as an absolute truth. Whether your estimated squat 1RM went from 140 to 152 over a block is a useful fact, even if neither figure is exactly what you would lift on the platform.
Only if you compete, or if you are curious and experienced enough to do it safely. A true 1RM attempt is a skill, it needs a spotter or safety bars, and it costs several days of recovery. For programming purposes the estimate is enough.
If you do test: work up in progressively smaller jumps, take 3–5 minutes between attempts, stop at the first genuine grind, and never test on a lift you have been having pain in.
| % of 1RM | Typical reps | Used for |
|---|---|---|
| 90–95% | 1–3 | Peaking, strength |
| 80–90% | 3–6 | Strength blocks |
| 70–80% | 6–12 | Hypertrophy |
| 60–70% | 12–20 | Volume, joint-friendly work |
| 50–60% | Technique, speed | Deloads and warm-ups |
Percentages have the same weakness as any fixed prescription: they assume today is an average day. In practice most people are better served by running percentages as a starting point and adjusting with RPE on the day.
One-rep max: the heaviest weight you can lift for a single repetition with correct technique. It is used to set training loads as percentages and to measure strength progress over time.
Use the Epley formula: one-rep max equals the weight multiplied by one plus the reps divided by 30. A hard set of five reps at 100 kg estimates a 117 kg one-rep max. The set must be taken close to failure for the estimate to mean anything.
Reasonably accurate from sets of six reps or fewer, often within a few percent. Accuracy degrades as reps rise, and at twelve reps the estimate can be out by ten percent or more. Rep endurance at a given percentage also varies by lift and by individual.
Only if you compete or have the experience and safety equipment to do it properly. A true attempt is a skill, requires a spotter or safety bars, and costs several days of recovery. For programming, an estimate from a normal working set is sufficient.
An estimated 1RM is most useful as a line on a chart. NutriMacro calculates it from the sets you log and tracks it per lift over months, which turns "am I stronger than in January" into something you can answer.
NutriMacro is a nutrition and training tracker for iPhone and Android. It logs food by barcode, photo or search, counts food in slices and units rather than grams, and keeps strength training, GPS activities, sleep and recovery in the same daily view. It runs in the language of your phone across 108 countries.
General training guidance for healthy adults. If you have an injury, a health condition or are new to lifting, get coaching on technique before chasing load.
Read next: What is RPE? Reps vs weight Progressive overload
