Header Logo - At most 215 pixels tall (Logos will be resized to a maximum height of 215 pixels)
Header Image - 1100 pixels wide not full width, 2000 pixels full width
Background Image - For non-repeating backgrounds, upload an image that is 2000 pixels wide.
Banner Image - 1110 pixels wide not full width, 2000 pixels full width
Social Sharing Tab - 1200 × 630 pixels
Merchandise - 240 x 240 pixels
Speaker Image Size - 600 x 600 pixels
However, for two and three speakers, the dimensions 1960 x 800 (or for compression reasons, 980 x 400)