One-Rep Max (1RM)

Estimate the most weight you could lift for a single rep, from a set you have done. Includes a table of training loads by percentage.

Weight lifted176 lb
Repetitions5 reps

Results update as you type

Estimated 1RM
202 lb
Epley 206 lb · Brzycki 198 lb
Training loads
100%202 lb~1 reps
95%192 lb~2 reps
90%182 lb~4 reps
85%172 lb~6 reps
80%162 lb~8 reps
75%152 lb~10 reps
70%142 lb~12 reps
65%131 lb~15 reps

Formulas use international (WHO) standards — healthy ranges are the same worldwide; only the units differ. The national context below uses U.S. data (CDC / NHANES).

Strength training in the U.S.

Strength training isn’t just about lifting more — it protects muscle, bone and metabolism. U.S. guidelines recommend it at least twice a week, a target most adults miss.

2×
Strength (CDC)
Sessions per week recommended
25%
Physically inactive
No leisure-time activity
1–5
For max strength
Reps per set (85–100% 1RM)
6–12
For hypertrophy
Reps (67–85% 1RM)

What one-rep max (1RM) is

Your 1RM is the most weight you could lift once with good form on a given exercise. It’s the reference for programming loads — most routines are written as a percentage of 1RM.

Because testing a true 1RM is demanding and risky, VitaDup estimates it from a set you’ve already done (weight × reps) using the Epley and Brzycki formulas.

Using the load table

From your estimated 1RM, the table shows the weight for each percentage and how many reps are typically possible. Use high percentages (85–95%) for strength, mid (67–85%) for muscle, and lower for endurance.

The estimate is most accurate with sets of 1–8 reps; error grows with very high reps.

Frequently asked questions

Is testing a true 1RM safe?

Only with experience, good form and a spotter. For most people, estimating from a submaximal set is safer and enough.

Why do Epley and Brzycki differ?

They’re two formulas; VitaDup shows both and their average. Differences are small at low rep ranges.

Does it work for any lift?

Best for big lifts (squat, bench, deadlift). It’s less reliable for small isolation moves.

Sources

Frequently asked questions

The most weight you can lift for a single repetition of an exercise.

From a weight and the reps you can do with it, using formulas like Epley or Brzycki — avoiding a risky true max attempt.

Good for lower rep counts (under about 10); accuracy drops as the reps rise.

Related calculators

Heart-Rate Zones
Your training zones by heart rate.
Daily Calories (TDEE)
Energy you burn per day.
Macro Split
Protein, carbs & fat targets.
Sister site
CountDup — Money math, solved — for your country.
Take-home pay, mortgages, taxes and the viral money comparisons people love — built country by country.
Open CountDup
Sister site
DaysDup — Days until anything — dates & holidays.
Countdowns, public holidays, age and business-day math — accurate for every country and year.
Open DaysDup

This tool is for general education and is not a substitute for professional medical advice.