Hi,
The specs shows:
Dimensions and weight:
Dimensions (W x D x H)
61.5 x 19 x 45.67 cm
Weight
11 kg
Package weight
14.4 kg
Source: http://www8.hp.com/ie/en/products/desktops/product-detail.html?oid=14977792#!tab=specs
No other information. I think the box is more than 3Kg that means you need to add 3 cm to 10 cm each size.
Regards.