SR Gym Surat / Calculators / One-Rep Max Calculator
Free Tool
One-Rep Max Calculator
You don’t need to attempt a max single to know your max. Enter a weight and the reps you got with it, and we’ll estimate your one-rep max plus the training percentages built off it.
Estimated one-rep max
0 kg
Estimates are most accurate at 1–8 reps and get rougher above that. A calculated max is a training guide, not a cue to load a real one-rep attempt without a spotter, proper warm-up, and good technique.
How to use your 1RM
We use the Epley formula: 1RM = weight × (1 + reps / 30). It’s most reliable when your set was in the 1–8 rep range — the further past that you go, the more it’s an educated guess.
The percentage table is where the real value is. Most strength programs are written in percentages of your max: heavy strength work sits around 80–90%, solid muscle-building work around 67–80%, and speed or technique work lower. Use the table to load your bar without guessing.
Your true max moves with sleep, stress, and how the day is going. Treat the number as a moving target, not a tattoo.
Questions
How accurate is a 1RM calculator?+
Very usable inside 1 to 8 reps — usually within a couple of percent. Past about 10 reps, fatigue and technique make it much less precise, so keep your test set heavy and clean.
Is it safe to test my actual one-rep max?+
It can be, but only with a thorough warm-up, solid technique, and ideally a spotter or a coach watching. For most people, estimating from a 3 to 5 rep set is safer and nearly as useful.
How do I use the percentages?+
Pick the percentage your program calls for and load the matching weight. For example, 5 sets of 3 at 85% would use the weight next to 85% in the table.
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Numbers are the easy part
A calculator gives you a target. A coach gets you there. Bring your result to the floor in Adajan.