https://liftnumbers.com/en/ Seven gym calculators built on one consistent set of formulas: 1RM, percentage charts, plate loading, RPE, Prilepin, strength standards and 5/3/1. Free, no sign-up. en https://liftnumbers.com/en/articles/how-much-is-four-plates/ https://liftnumbers.com/en/articles/how-much-is-four-plates/ Tue, 25 Aug 2026 00:00:00 GMT One plate, two plates, four 45s on each side — gym shorthand states loads as plate counts rather than weights. Here is the full conversion, in pounds and kilos, and where the numbers come from. https://liftnumbers.com/en/articles/warm-up-sets/ https://liftnumbers.com/en/articles/warm-up-sets/ Fri, 21 Aug 2026 00:00:00 GMT A warm-up is not an opening ritual but part of the session's design. Too little and the first work set is wasted; too much and it is already fatigued — and both mistakes are avoidable with a few percentages. https://liftnumbers.com/en/articles/rounding-and-the-smallest-plates/ https://liftnumbers.com/en/articles/rounding-and-the-smallest-plates/ Fri, 21 Aug 2026 00:00:00 GMT The calculator says 113 kg. The bar takes 112.5 or 115. The gap is small, but it recurs every session — and on the lightest lifts it is the single most common reason progress stops. https://liftnumbers.com/en/articles/prilepins-chart-explained/ https://liftnumbers.com/en/articles/prilepins-chart-explained/ Fri, 21 Aug 2026 00:00:00 GMT Prilepin's chart tells you how many reps belong at a given percentage. It is a useful yardstick, but it came out of weightlifting — and that explains both what it is good for and where it stops applying. https://liftnumbers.com/en/articles/what-is-a-good-bench-press/ https://liftnumbers.com/en/articles/what-is-a-good-bench-press/ Fri, 21 Aug 2026 00:00:00 GMT A hundred kilos means something different at 60 kg bodyweight than at 100. The usual answer — "one and a half times bodyweight" — is a useful rule of thumb, but it is unfair to lighter lifters, and the reason is geometry. https://liftnumbers.com/en/articles/limits-of-the-percentage-chart/ https://liftnumbers.com/en/articles/limits-of-the-percentage-chart/ Fri, 21 Aug 2026 00:00:00 GMT The chart says five reps is 87 % of your max. For some lifters it is 80 %, for others 92 %. That spread is not an error in the chart — it is what a chart is — and understanding it makes the chart more useful, not less. https://liftnumbers.com/en/articles/rpe-and-rir/ https://liftnumbers.com/en/articles/rpe-and-rir/ Fri, 21 Aug 2026 00:00:00 GMT RPE 8 means you could have done two more reps. That is the whole concept — but it leads to a way of adjusting load to the day that a fixed percentage program cannot do. https://liftnumbers.com/en/articles/weight-plate-colours/ https://liftnumbers.com/en/articles/weight-plate-colours/ Fri, 21 Aug 2026 00:00:00 GMT There is nothing arbitrary about weightlifting plate colours. They are an international standard designed so that the load on a bar can be read from across the room — and once you know the code, you never have to count a bar again. https://liftnumbers.com/en/articles/how-much-does-a-barbell-weigh/ https://liftnumbers.com/en/articles/how-much-does-a-barbell-weigh/ Fri, 21 Aug 2026 00:00:00 GMT An Olympic barbell weighs 20 kg, a women's bar 15 kg. But the rack holds plenty of bars that weigh neither — and because the bar is part of every calculation, an error there passes straight through to every percentage you train with. https://liftnumbers.com/en/articles/531-vs-8x3-progression-compared/ https://liftnumbers.com/en/articles/531-vs-8x3-progression-compared/ Wed, 19 Aug 2026 00:00:00 GMT Two popular ways to structure a session look like they differ in sets and reps. The real difference is what decides when the load goes up – the calendar or your performance. https://liftnumbers.com/en/articles/how-often-to-test-your-max/ https://liftnumbers.com/en/articles/how-often-to-test-your-max/ Wed, 19 Aug 2026 00:00:00 GMT A max is an appealing number because it is unambiguous. But progress comes from the sets performed below it – and that number can be estimated accurately enough without testing at all. https://liftnumbers.com/en/articles/comparing-1rm-formulas/ https://liftnumbers.com/en/articles/comparing-1rm-formulas/ Tue, 18 Aug 2026 00:00:00 GMT Epley, Brzycki, Lombardi, Wathan and O'Conner give different answers for the same set. The difference isn't an error – it follows from how each formula models the relationship between reps and load, and it grows quickly past five reps.