Bumping this down.

This is really helpful, although I don't need it immediately. I was wondering how to work out the length of plastic gas pipe I needed to make a cover for my winter brassicas. (not to protect them from cold but to net them against wood pigeons which can destroy them here.)

And it even does that new-fangled metric measuring style :)

Ha ha. I'm old enough to be able to do Imperial or metric.