Sitecore Web Image Sizes

Sitecore Classic (Homepage, academic, department sites)

For formatting homepage hero images, see this page:  /wiki/spaces/UC/pages/34341770

Department hero image1760px wide (save at ~100–200KB) - most hero images are 1760 x 620
Body copy image1500px wide (save at ~100–200KB)
Callout800 x 462px (save at ~50KB)
News / F&S bulletin image

292 x 210px (save at ~5–10KB)

F&S bulletin header640x220px
Events492 x 370px
News / events detail
image (larger)
1152px wide (save at ~30KB)
F&S directory profile

320 x 400px (save at ~20KB)

Use the guidelines in this file to line up the top & bottoms of heads: directory-photo.psd

F&S directory thumbnail200 x 200px (save at ~15KB) 
Newsletter banner image1000x650px
Newsletter content (max-width)577x433px (4:3), 577x325px (16:9)

Sitecore Marketing Template (Undergraduate Admissions, SFS, Alumni)

Hero Image2500 × 1667px (300-400 KB is acceptable ~10% quality)
Page Feature Panel Image1640 x 1000px (100-200 KB ~20%–50% quality)
Parallax image

2500x1667 (300-400 KB is acceptable ~10% quality)

Body Copy Image1170 × 778px (100-200 KB ~20%–50% quality)
Callout792 x 594px (100-200 KB ~20%–50% quality)
Gallery Thumbnail760 x 388 (20% quality)
Gallery Full-size

1600px at largest dimension (keep around 300–400KB),

these can also be portrait-oriented

etc Cover Image1034 x 1277 (10-20% quality)
etc Story Feature1168 x 636 (20-30% quality)
Tile Card582x300px

Wordpress (SPU Stories)

Hero image 2800x1344 (landscape), 1200x1600 (portrait)
Body content images (wrapped)300x169px (16:9), 300x225 (4:3), 300x400 (portrait)
Body content images (full-width)2160x1215 (16:9), 2160x1620(4:3)

Mailchimp Image Sizes

Header image 1000x530px
Square images in list200x200px
Faculty images160x220px

For more information on email templates/images see this page: /wiki/spaces/UC/pages/34342052

Slate Email

Body content (max-width)800x450px (16:9), 800x600px (4:3)

Social Media 

Instagram and Facebook feed, marketplace, Instagram explore, messenger inbox, Facebook groups and in-stream video1:1 aspect ratio

Facebook Search, right column instant articles and messenger messages

Facebook/Instagram stories, messenger stories, audience network native banner and interstitial9:16 

General Facebook size specs

1200x628; 1.91:0 aspect ratio (landscape)
General Instagram size specs1080x1080; aspect ratio 1:1 (square)
General Snapchat size specs1080x1920; video: 1080x1920 (shot vertical) mp4 or mov (3-6 seconds)