i don't have an iphone but I have an LG rumor...the dimensions for that are 4.29" x 2.00" x 0.70
the iphone dimensions are 4.5 x 2.4 x 0.46
the iphone is a my lg has about a thumbswidth left on the sides and fits up the where the flap folds over (and there's about a half inch of empty space from top)
my phone also fits perfectly in the pouch widthwise...you iphone is just alot thinner so there will be extra space inside the pouch itself