Plate Loading Calculator
Compute which plates to load onto a barbell to reach a target weight.
Overview
A plate-loading calculator solves the small arithmetic puzzle of which plates to slide onto a barbell to reach a target lift weight. It is most useful for athletes who train across kilograms and pounds, who alternate between standard Olympic gyms and home garages with mismatched plate sets, or who are simply tired of doing the maths between heavy sets.
The output is a clean "per-side" plate list, since loading is always symmetric. Most calculators support both metric and imperial plate stacks, optional smaller change plates (1.25 kg, 0.5 kg, 2.5 lb), and a configurable bar weight — typical Olympic bars are 20 kg or 45 lb, but training bars run lighter, and specialty bars vary widely.
How it works
The algorithm starts by subtracting the bar weight from the target and halving the remainder to get the per-side load. It then applies a greedy descent through the available plate sizes — heaviest first — pulling the largest plate that does not overshoot, then repeating until the remainder hits zero or is smaller than the smallest plate. Any leftover difference is reported so you know the closest achievable weight.
For example, with a 20 kg bar, a target of 100 kg, and a standard set of 25 / 20 / 15 / 10 / 5 / 2.5 / 1.25 kg plates: per side load is 40 kg, which the greedy decomposition resolves as one 25 kg, one 15 kg. With a target of 102.5 kg the per-side load is 41.25 kg, resolved as 25 + 15 + 1.25.
Examples
- Target 60 kg on a 20 kg bar: per side 20 kg = one 20 kg plate (or two 10s).
- Target 142.5 kg on a 20 kg bar: per side 61.25 kg = 25 + 25 + 10 + 1.25.
- Target 225 lb on a 45 lb bar: per side 90 lb = 45 + 45 (the classic "two plates").
- Target 87.5 kg on a 15 kg "lady" bar: per side 36.25 kg = 25 + 10 + 1.25.
FAQ
Does the order of plates matter?
Mechanically, no. Aesthetically, loading heaviest-inside-to-lightest-outside is standard and makes weight changes faster.
What about collars?
Most gyms ignore the 2.5 kg of typical spring or lock-jaw collars; competition collars add a known weight. Tell the calculator if you want them included.
Why does my gym only have 45 lb plates?
Imperial plates step in 5 lb increments down from 45. The calculator handles both systems and warns when a target is not achievable.
Can I mix kg and lb plates?
Possible but messy. Stick to one unit per bar to avoid arithmetic mistakes.