How it works
Add an exercise and log each set as you lift it: weight and reps, then tick. The next time you add that exercise, every box already shows last session's numbers in grey, set by set, warm-ups matched to warm-ups. Tick an untouched row to repeat last time, or type over it. When a set beats last time, the row says by how much; when it doesn't, it says nothing.
Ticking a set starts the rest timer: 2 minutes unless you change it for that exercise. The American College of Sports Medicine recommends at least 2 to 3 minutes for heavy compound lifts and 1 to 2 for assistance work.
"Load the bar" works out the plates for each side, heaviest first, from the plates you have. Kilogram plates are drawn in the IWF's competition colors.
The estimated one-rep max uses the Brzycki formula on sets of 10 reps or fewer. It's an estimate: these formulas get less reliable as reps go up.
Pounds are converted at exactly 0.45359237 kg (NIST). Workouts stay in this browser on this device, so export a copy now and then: the tool reminds you after a few workouts.
Questions people ask
- How long should I rest between sets?
- For heavy compound lifts like the squat and bench press, the American College of Sports Medicine recommends at least 2 to 3 minutes; for assistance exercises, 1 to 2 minutes may be enough. In one 8-week study of 21 trained men, 3-minute rests built more strength than 1-minute rests. The rest timer here starts at 2:00 and can be set per exercise.
- How is the estimated one-rep max worked out?
- With the Brzycki formula, weight × 36 ÷ (37 − reps), for sets of 10 reps or fewer; 100 kg for 5 reps estimates 112.5 kg. It's an estimate, not a tested max: rep-based formulas are most accurate near your true max, so higher-rep sets get no estimate here.
- How much does an Olympic barbell weigh?
- A men's competition bar weighs 20 kg and a women's 15 kg, under the International Weightlifting Federation's rules. In pound gyms the 20 kg bar is usually called 45 lb (it's 44.1 lb). Competition collars add 2.5 kg each.
- What do the plate colors mean?
- They're the IWF's competition colors: 25 kg red, 20 kg blue, 15 kg yellow, 10 kg green and 5 kg white, with the small 2.5 to 0.5 kg discs repeating red, blue, yellow, green, white. Gym plates vary, and many are plain black iron; the calculator uses the competition colors for kilograms.
- When should I add weight?
- The ACSM's guideline is to add 2 to 10% once you can do one or two reps more than your target on two sessions in a row. The grey numbers in each box show what you did last time, so you can see when that's happened; the log never picks the weight for you.
Sources
- IWF Technical and Competition Rules and Regulations, 2020 (bars, collars, discs, colors, loading)
- NIST SP 811, appendix B.8 (pound to kilogram)
- ACSM 2009: progression models in resistance training for healthy adults
- Schoenfeld et al. 2016: longer interset rest periods enhance muscle strength and hypertrophy
- 1RM prediction equations, including Brzycki (Table 1)
- Accuracy of 1RM prediction from repetitions
- Strong help: 1RM (Brzycki formula, limits above 12 reps)
- Strong help: rest timer (2:00 default)
- REP Fitness: color bumper plates in pounds
- REP Fitness: 20 kg (44.1 lb) power bar