# Crossing number of simple undirected graph

There's a well-established result which provides a lower bound for the crossing number of any simple undirected graph. However, is there any known result for an upper bound in this setting?

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 The tag graph is intended for questions about graphs of functions, see the tag-wiki and the tag-excerpt. (The tag-excerpt is also shown when you are adding a tag to a question.) There is a separate tag for graph-theory. – Martin Sleziak Mar 14 at 10:34 If the graph has $m$ edges then $\binom{m}{2}$ is tight. You could object that you want to use straight lines, but that is not a requirement for the lower bound version of the problem. – Chris Godsil Mar 14 at 12:06