⚙️Plate calculator
Stop doing barbell maths mid-set. Enter the weight you want and the bar, get the plates per side.
How plate maths works
A loaded barbell is symmetrical, so the only question is what goes on ONE side. Subtract the bar, halve what is left, then fill that half with the largest plates that fit:
per side = (target - bar weight) / 2
Olympic bar 20 kg · women's bar 15 kg · EZ bar ~7-10 kgLoading heaviest-first is not just tidiness. Big plates sit flush against the collar, which keeps the load stable and stops the bar whipping on the way up.
A worked example
100 kg on a 20 kg Olympic bar:
(100 - 20) / 2 = 40 kg per side
40 = 20 + 20 (or 20 + 15 + 5, or 20 + 10 + 10)When the number is not loadable
Not every weight can be built. With standard kilo plates the smallest jump is 2.5 kg total - 1.25 a side - so a programme asking for 83 kg wants either 82.5 or 85. Round down rather than up: the extra rep you keep is worth more than the extra kilo you miss.
- Micro plates of 0.5 or 1.25 kg make small increases possible on presses, where 2.5 kg jumps stall early.
- Gym bars are not all 20 kg. Weigh yours once and stop guessing.
- Pounds and kilos do not mix cleanly. Pick the unit your gym uses and stay in it.
Common questions
Does the bar count in the total?
Yes. "100 kg on the bench" means bar plus plates. Logging plates only will overstate your progress by a fixed 20 kg, which is a lot when you compare lifts.
Why load the heaviest plates first?
They sit flush against the collar, which keeps the load stable and reduces bar whip. It also makes the load readable at a glance.
What if I cannot make the exact weight?
Round down and add a rep instead. Volume is what drives adaptation, and a missed rep at a rounded-up weight costs more than the kilo gained.
Are colour-coded plates standard?
In competition, yes - red 25, blue 20, yellow 15, green 10. Commercial gyms often ignore it, so read the number rather than trusting the colour.
Estimates for general fitness guidance, not medical advice.