Links are counted by their spacing, centre to centre, along the run they sit on. It sounds simple, and it is, but there is one mistake nearly everyone makes once: adding a link for the end.
The rule
The number of links is the length of the run divided by the spacing, rounded down. A 3 metre run with links at 250 mm centres gives 3000 divided by 250, which is 12 links. Not 13.
The temptation is to count fence posts: twelve gaps make thirteen posts. But the links in a foundation do not sit at both ends of every run like that, and the ends usually meet the next run, where a link is already counted. Add one for the end of every run and you count double at every corner.
Round down, but never to zero
A run shorter than one spacing gives zero when you divide and round down. But a run that exists needs at least one link. So the floor is one: a 200 mm run at 250 mm centres gets one link, not zero.
This is exactly the rule Mängda counts with: the length divided by the spacing, rounded down, and at least one per run. A run that dropped out of the bill because it came to zero would be worse than one that came out one short, because nothing on screen says it went missing.
Where the sizes come from
- The length of the run comes from the plan. That is where the links repeat.
- The shape of the link and its leg lengths come from the section, in millimetres.
- The spacing is usually on the section or in the reinforcement schedule.
From a count to an order
With the number of links and their leg lengths you have the total bar length, and from it how many whole bars you need. Count in whole bars, not metres: half a bar cannot be ordered.