Designing a Facebook  Cover? is all about Pixels!

✓851 Pixels Width includes 1px transparent gray border that Facebook overlays on the left and right edges
✓315 Pixels Height includes 1px transparent gray border that Facebook overlays on the bottom edge and 1px of height that becomes hidden under the Facebook header bar.
Total visible area is 314px
✓103 Pixels cut-out height not including top border overlay✓24 Pixels distance between lefth edge and inset profile icon including 1px border overlays
✓160 x160 Pixels Profile Icon/Picture shown is 160x160px but min upload size is 180x180px
168px width of the cut out space not including border overlays

Facebook Covers