How much you are really training

In weight training, "volume" can be counted in two ways: tonnage, that is load times reps times sets, and the number of working sets per week for each muscle group. The first is easy to calculate but misleading; the second is the one research most often uses to relate training to muscle growth. This calculator shows both, together with intensity relative to your one-rep max and an estimate of how close you are to failure.

It works in kilograms or pounds: just use the same unit for load and one-rep max.

How the calculation works

You enter the load, reps per set, sets per session, how many sessions a week you train that muscle group and your one-rep max (1RM) for that exercise.

• Weekly sets: sets per session × sessions per week.
• Volume per session: load × reps × sets.
• Intensity: load divided by one-rep max.
• Reps in reserve: the maximum reps estimated with the Epley formula, 30 × (one-rep max / load − 1), minus the reps you actually do.

The verdict is based on weekly sets per muscle group, the measure used by the main meta-analyses on hypertrophy.

Weekly sets matter more than tonnage

A 2017 meta-analysis by Schoenfeld, Ogborn and Krieger found a dose-response relationship between weekly sets and muscle growth: on average, people doing at least 10 sets a week per muscle gained more than those doing fewer than 5. Counting sets is simple and works for any exercise and load, as long as the sets are working sets, that is close enough to failure.

Same tonnage, different stimulus

Tonnage adds up the weight lifted but says nothing about how demanding each set was. The table shows four sessions with the same tonnage, 2,400, for someone with a one-rep max of 120.

The number is identical, but the first session takes every set to failure and the last leaves dozens of reps in reserve. That is why the calculator shows sets and reps in reserve alongside tonnage.

Intensity and possible reps

The Epley formula estimates how many reps you can do at a given percentage of your one-rep max. It is most reliable up to 10–12 reps; beyond that, individual differences grow.

If you do more reps than estimated, your real one-rep max is probably higher than the one you entered: the calculator flags it.

How close to failure

Reps in reserve show how many more you could have done. Much practical guidance suggests ending working sets with about 0–3 reps in reserve: close enough to failure for each set to count, without always reaching it, so that fatigue stays manageable. Sets very far from failure count little as a stimulus, even if they push tonnage up.

The four bands of the verdict

• Below 5 sets a week: low volume, suited to starting out or maintenance.
• 5 to 10: moderate volume, a good base to build on.
• 10 to 20: the range associated with the greatest muscle gains for most trained people.
• Above 20: high volume, where recovery becomes the limit.

Spreading sets across the week

The same number of weekly sets can be done in a single session or spread over two or three. With many sets, splitting them across several days reduces the fatigue of each session and helps keep the quality of the last sets. That is why the calculator asks for sessions per week for the muscle group: twelve sets can be 12 × 1, 6 × 2 or 4 × 3.

How to count sets per muscle group

Count as sets for a muscle those from exercises in which that muscle is a prime mover: for the chest, bench press and flyes; for the quadriceps, squats and leg press. Exercises in which a muscle works as a secondary mover, such as the triceps in the bench press, count partly. Use the calculator for one exercise or for the total sets of several exercises for the same group, entering the load and one-rep max of the main one.

Limits of the calculator

The model uses the Epley formula, which is an estimate and varies between people and exercises. Ideal volume depends on experience, age, recovery, sleep and nutrition, and there is no number of sets that suits everyone. The calculator is for measuring and comparing your training, not for replacing a qualified professional; if you have pain or health problems, consult a doctor.

Frequently asked questions

How is training volume calculated?

In two ways: tonnage, that is load times reps times sets, and working sets per week per muscle group. The calculator shows both.

How many sets per week per muscle do I need?

Meta-analyses associate the greatest muscle gains with about 10–20 working sets per week per muscle for most trained people. Beginners also get results with fewer.

Why is tonnage not enough?

Because it adds up the weight but does not say how demanding each set was: the same tonnage can come from sets to failure or from very light sets, with different stimuli.

What are reps in reserve?

The reps you could still have done at the end of the set. Much practical guidance suggests ending working sets with about 0–3 reps in reserve.

How are maximum reps estimated?

With the inverted Epley formula: 30 × (one-rep max / load − 1). It is most reliable up to 10–12 reps.

What does intensity as % of one-rep max mean?

It is the load divided by your one-rep max. At 75% people usually manage about 10 reps, at 85% about 5.

I don't know my one-rep max: what should I do?

You can estimate it with the one-rep max calculator from a set of a few reps taken close to failure, then enter it here.

Is it better to do all sets in one day or split them?

With many sets, splitting them over two or three sessions reduces the fatigue of each session and helps keep the quality of the last sets.

Does it work in pounds?

Yes: use the same unit for load and one-rep max. Tonnage will be expressed in that unit.

How do I count sets if I do several exercises for the same muscle?

Add up the sets of exercises in which that muscle is a prime mover. Exercises in which it works as a secondary mover count partly.

Is more volume always better?

No: beyond a certain point recovery becomes the limit and gains slow down. Volume should be increased gradually, watching progress and fatigue.

Does the calculator replace a coach?

No. It measures your training with standard formulas; for personalised programmes or if you have pain, see a qualified professional or a doctor.