See www.zabbix.com for the official Zabbix site.
Remove graphs width and height attributes
Graphs in Zabbix have width and height attributes. These attributes usage in frontend is inconsistent. Width is used only for graphs preview and pie graphs in monitoring->graphs. Height is used in Monitoring->graphs, but calculated differently for graph types. For normal graphs height is defined for chart plotting area, but for pie charts it includes legend.
Remove width and height parameters for graphs. For both graph types height is hardcoded to 200px for plotting area, legend calculated separately. Width depends on browser window width for normal graphs (as it is now) and hardcoded to default value for pie graphs.
In screens each cell has it own width/height which is used to display graphs.