predicting encrypted data size with Rijndael

From: z f (dont_at_send.mails)
Date: 11/15/05

Date: Tue, 15 Nov 2005 16:45:35 +0200

i use Rijndael encryption with key of 32 bytes.
how can i predict the maximum size of data needed to be allocated to the
encrypted data knowing the size of the clear text before encryption?