Free Strength Tools and Calculators
Section updated .
Four free calculators for the training decisions that come down to arithmetic: estimating a one-rep max from a hard set, turning reps and RPE into a working weight, working out which plates go on the bar, and totalling a week of sets by muscle group. Each uses only the numbers you type, shows its working, and runs in your browser.
Every tool page states its method in plain words, gives guidance for each of the five reader profiles this briefing serves (beginner, intermediate, advanced, coach and returning lifter), and works through an example with clearly hypothetical numbers, so you can reach the same answer on paper if you prefer. Nothing you type leaves your browser, and nothing is stored.
The tools
One-Rep Max Estimator
Turn a hard set of 2 to 10 reps into an estimated one-rep max using two common equations, shown side by side.
Open the tool →Barbell Plate Loading Calculator
Work out which plates go on each side of the bar for a target weight, using only the plates you have.
Open the tool →RPE Load Calculator
Convert a planned set of reps at a chosen RPE into an approximate percent of your one-rep max and a working weight.
Open the tool →Weekly Sets Counter
Add up a week of hard sets by muscle group and compare each with the range in the ACSM position stand.
Open the tool →How to use these well
Read your own figures first: the weight and repetitions from a recent hard set, the stamped weight on your bar, the plates your gym actually has, and your sets from a training log. The boxes start with hypothetical example values so each page works at first glance; replace them with yours. These tools are general information, not coaching or medical advice: stop a set for sharp pain, and see a qualified clinician about pain that persists. For how to put the numbers into a plan, see the progressive overload guide.
Frequently asked questions
Are these strength tools free?
Yes, all of them, with no sign-up. Each runs entirely in your browser, so nothing you enter is sent anywhere and nothing is stored after you close the page.
Do the tools give medical or coaching advice?
No. They do arithmetic on the numbers you enter and describe the result. They cannot see your technique, your health history or how you feel today, so use them as a starting point and talk to a qualified coach or clinician about your own situation.
How accurate are the results?
They are estimates built from stated formulas, and each page shows the method in words so you can check the working. The one-rep max and RPE tools are approximations that vary by exercise and by person, and the volume counter compares your week with one published range, not with a personal target.
Do the tools know my bar, my plates or my lifts?
No, deliberately. You supply the weights, repetitions and sets. The values pre-filled in each form are hypothetical examples.
Do they work offline?
Yes. The pages and the calculations are self-contained, so they keep working without a connection once the page has loaded.
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