SMS messages can have no more than 160 characters.

On some wireless carriers, due to a programming convention called percent-encoding, certain symbols require more than one character when used. For example, the symbol "&" will display as one character when viewed on a mobile device, but actually requires the use of three characters to implement. The character counter below takes these factors into account—feel free to use it when building messages for your next campaign.

Other symbols in this category include:
@  #  $  %  &  [  ]  ;  :  ,  ?  +  =  /