Training calculators
One rep max, volume, rest, progression, and the heart rate numbers for the cardio side. 28 calculators for the hours you spend in the gym.
Training numbers do two separate jobs. Some of them decide what goes on the bar today, like an estimated one rep max or a warm up ladder. The rest tell you whether this month was genuinely harder than last month, which is the question progress actually turns on.
If you are newer to lifting, three of these cover most of it: an estimated max, a split that fits the days you can really commit to, and a progression step that says what to add next week. The rest are here for when a specific question comes up mid session.
There is a plain English glossary in the list too, because a fair amount of the difficulty in training advice is vocabulary rather than the training itself.
Where most people should begin
Three calculators that between them will plan a week of training without you reading anything else.
- 01
One Rep Max
Estimate your max from a set you have already done, with no max attempt and no spotter needed.
Open the calculator - 02
Workout Split
A training split built around the number of days you can honestly commit to, not the number you wish you had.
Open the calculator - 03
Progressive Overload
What to add next session, and when adding nothing at all is the right call.
Open the calculator
Every training calculator
All of them are free, none of them needs an account, and what you enter in one carries across to the next.
28 in this category
What the output is telling you
Numbers for today, numbers for the month
A warm up ladder and a plate breakdown are for the next ten minutes. Volume load and workout density are for looking back over eight weeks. Both are useful, and confusing the two is how people end up chasing a session instead of a trend.
Percentages you can plan with
Once you have an estimated max, the RPE chart, training max, warm up and rep range tools all speak the same language, so a programme written in percentages becomes actual weights.
The vocabulary too
AMRAP, RPE, deload, top set. The glossary defines every term the rest of the site uses, in one place, without assuming you already know the one next to it.
What a calculator cannot see
Every calculator here is a general fitness estimate rather than medical advice, and the things below are worth knowing before you act on one.
An estimate is not a max
A calculated one rep max comes from a curve fitted to a lot of lifters. It gets less accurate the further your set sits from a true max, so a set of twelve predicts much worse than a set of three.
Technique is invisible here
No calculator knows whether your last rep moved well. If the number and the bar disagree, believe the bar, and drop the load until the movement looks like the one you meant to do.
Load is one input of several
Sleep, food and stress move what you can lift on a given day by more than most people expect. The readiness and recovery checks on the wellness page exist for exactly that reason.
Answered here, not behind a signup
- How accurate is a one rep max calculator?
- Close enough to programme from when the set you enter is in the one to five rep range. Past about eight reps the estimate drifts, because endurance starts to matter more than maximum force and the formulas were never fitted to that. Enter your heaviest recent set of five or fewer for the best read.
- What does RPE mean?
- Rate of perceived exertion. On the lifting scale, RPE 8 means you could have done two more reps, RPE 9 means one more, and RPE 10 means nothing was left. The RPE calculator converts between that scale and percentages of your max, which is how most written programmes are expressed.
- How long should I rest between sets?
- It depends on what the set was for. The rest period guide gives a range by training goal, with heavy strength work sitting at the long end and higher rep accessory work at the short end. If the next set feels compromised by the last one, you probably went too early.
- How often should I train each muscle?
- The training frequency calculator gives you a range per muscle group based on how you train and how much you recover. Most people doing general strength work land on twice a week per muscle, which usually means fewer sets per session than they expect.
The other categories
- Body composition calculators14BMI, body fat, lean mass, FFMI, and the rest of the measurements that split scale weight apart.
- Nutrition calculators23Maintenance calories, macro splits, protein targets, and the intake numbers that sit on top of them.
- Wellness and recovery calculators12Sleep timing, stress and recovery checks, hydration, steps, and the unit converter everything else needs.
Not sure which number you need?
The full index has every calculator on the site with a search box, and the guided flows walk you through a set of them in order when one number on its own is not the answer.