Enter the total weight you lifted and the number of reps into the calculator to determine your estimated 3 rep max.
Safety note: This calculator provides an estimate only. Use proper form, warm up, and use a spotter/safeties for heavy barbell lifts. Do not attempt a new max based only on this number. If you’re new to lifting, injured, pregnant, have cardiovascular risk, or have been advised to avoid heavy exertion, consult a qualified coach or clinician.
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3RM Formula
The following formula is used to estimate a 3 repetition maximum weight.
3RM \approx 1RM \times 0.93
- Where 3RM is your 3 rep max
- 1RM is your 1 rep max
A common estimate is 3RM ≈ 90–95% of 1RM (often ~93%), but it varies by lift and individual.
3RM Definition
What is 3RM?
3RM is a term used in the fitness world to describe the maximum amount a person can lift 3 times. In other words, the person's three rep max.
How much is my 3 rep max?
A 3 rep max is estimated to be around 93% of the weight of your one-rep max. This will vary slightly depending on the exercise, but in general, the average is 93% of 1 rep max.
Example Problem
How to calculate 3rm?
- First, choose a weight you can lift with good form for about 3–10 reps (leave ~1–2 reps in reserve).
For this example, a person bench presses 225 lbs for 8 controlled reps, stopping before form breaks. Use a spotter and safeties for barbell lifts.
- Next, determine the estimated max lift.
Using the calculator linked above, the max lift of this bench press is estimated to be 272.25 lbs.
- Finally, calculate the 3-rep max.
Using the formula above, the 3 rep max is calculated to be:
3RM = 1RM*.93
3RM = 272.25 *.93
3RM = 253 .19 lbs.
