How does the plate loading calculator work?

It uses a greedy algorithm: per-side weight = (target − bar weight) / 2. Starting from the heaviest available plate, it places as many of that plate as fit, then moves down to the next denomination until the per-side weight is accounted for exactly. This matches how an experienced lifter loads a bar — largest plates closest to the sleeve collar, smallest outermost.

What plate denominations are included?

The kg set mirrors the standard IWF / IPF Olympic set: 25, 20, 15, 10, 5, 2.5, 1.25, 0.5, and 0.25 kg. The lb set mirrors a standard US commercial gym: 45, 35, 25, 10, 5, 2.5, and 1.25 lb. These cover the vast majority of loading scenarios in any well-equipped gym.

What if my target weight is not achievable with standard plates?

Not every kilogram or pound value can be built from standard plate denominations. If your target cannot be assembled exactly, the calculator flags the gap and suggests adjusting your target. For example, 101 kg cannot be made with a 20 kg bar and standard kg plates — 100 kg or 102.5 kg can.

What is the correct plate loading order on the bar?

Always load the heaviest plate first (closest to the collar) and the lightest last. This keeps the bar balanced during loading and is the convention enforced at all sanctioned competitions. Never place a lighter plate between two heavier ones, as this creates uneven stress on the sleeve.

Does bar weight include collars?

Technically no — competition collars weigh 2.5 kg (5.5 lb) each, adding 5 kg / 11 lb to the total. Most lifters omit them in training log totals. If precision matters, subtract collar weight from the bar field (e.g., enter 15 kg instead of 20 kg when using 20 kg bar + 2.5 kg collars).

What are the standard Olympic barbell weights?

The most common bars are: 20 kg / 44 lb (men's Olympic bar, 2.2 m, 28–29 mm shaft), 15 kg / 33 lb (women's Olympic bar, 2.01 m, 25 mm shaft), and 20 kg / 44 lb (powerlifting bar, 2.2 m, 28–32 mm). Trap/hex bars vary from 18–34 kg depending on manufacturer — weigh yours or check the product spec before logging totals.

Plate Loading Calculator

A barbell plate loading calculator tells you exactly which plates to put on each side of the bar to hit a target total weight. Instead of doing mental arithmetic under fatigue — or worse, loading the bar unevenly — you type in the target weight, choose your unit system, and read off the plate list in seconds. It covers both the Olympic kilogram set used internationally and the standard US pound set found in most commercial gyms.

How it works

The maths behind plate loading is straightforward but easy to get wrong in your head, especially when fatigue sets in mid-session.

Step 1 — calculate per-side load:

Per-side weight = (Target total − Bar weight) / 2

So for a 100 kg squat with a 20 kg bar:

Per-side = (100 − 20) / 2 = 40 kg per side

Step 2 — greedy plate assignment (largest first):

Starting from the heaviest available plate, the algorithm places as many of that plate as will fit without exceeding the per-side remainder, then moves to the next denomination:

Plate	Fits?	Running subtotal
25 kg	1 × 25 = 25 kg (≤ 40)	25 kg used, 15 kg left
20 kg	0 (20 > 15)	—
15 kg	1 × 15 = 15 kg (≤ 15)	40 kg used, 0 left

Result: 1 × 25 kg + 1 × 15 kg per side, giving 40 + 40 + 20 bar = 100 kg total.

This greedy approach always uses the fewest plates possible while keeping the heaviest weights innermost — exactly the loading convention used at Olympic Weightlifting and Powerlifting competitions.

Worked example — powerlifting total

A lifter working up to a 140 kg / 308 lb deadlift using a standard 20 kg bar:

Per side = (140 − 20) / 2 = 60 kg per side

Greedy assignment from the standard Olympic set:

2 × 25 kg = 50 kg — 10 kg remaining
1 × 10 kg = 10 kg — 0 remaining

Load: 2 × 25 kg + 1 × 10 kg per side — five plates total across both sides.

The same weight in pounds (308 lb with a 45 lb bar):

Per side = (308 − 45) / 2 = 131.5 lb per side

2 × 45 lb = 90 lb — 41.5 lb remaining
1 × 35 lb = 35 lb — 6.5 lb remaining
1 × 5 lb = 5 lb — 1.5 lb remaining
1 × 1.25 lb = 1.25 lb — 0.25 lb remaining (within tolerance)

Load: 2 × 45 + 1 × 35 + 1 × 5 + 1 × 1.25 lb per side.

Formula note

The core formula is:

plates_per_side = greedy_decompose((W_target − W_bar) / 2, plate_set)

where greedy_decompose iterates the plate set in descending order:

remaining = per_side
for each plate p (heaviest first):
    count[p] = floor(remaining / p.weight)
    remaining = remaining − count[p] × p.weight
if remaining > tolerance → "not achievable with this plate set"

A tolerance of ±0.01 kg is applied to absorb floating-point rounding. Targets that fall between achievable increments (e.g., 101 kg on a 20 kg bar, which needs exactly 40.5 kg per side but the smallest kg plate is 0.25 kg so 40.5 kg is achievable — 101 kg IS reachable with 1 × 25 + 1 × 15 + 2 × 0.25) are handled automatically. The calculator will report “not achievable” only when no combination from the standard set can build the exact per-side weight.

Plate colour conventions

International competition follows the IWF colour code:

Red — 25 kg
Blue — 20 kg
Yellow — 15 kg
Green — 10 kg
White / grey — 5 kg and below

The barbell diagram in the calculator mirrors these colours so you can visually cross-check the loaded bar before lifting.