Here are a few image resolution size rules to follow when uploading your banners to social media. We have added just a few here with a referral link at the bottom to the original article for the full Cheatsheet on all social networks.
INSTAGRAM IMAGE SIZING RULES
Profile Picture: 110 x 110 pixels
Photo Size: 1080 x 1080 pixels (square)
Photo Size: 1080 × 1350 pixels (full size expanded)
Photo Thumbnails: 161 x 161 pixels
IMAGE SIZING FOR FACEBOOK
Cover Photo: 828 x 315 pixels (a preferred maximum file size of 100 KB)
Profile Picture: 180 x 180 pixels
Shared Image: 1 200 x 630 pixels
TWITTER IMAGE SIZING
Profile Photo: 400 x 400 pixels (a maximum 100 KB file size)
Header Photo: 1 500 x 500 pixels (a maximum 10 MB file size)
IMAGE SIZING GUIDELINES FOR GOOGLE+
Profile Image: 250 x 250 pixels
This Image is your identity across all Google Network, It appears as a circle so make sure all important elements are kept to the center.
Cover Picture: 1 080 x 608 pixels
This image can have your brand, logo and business tagline.
Shared Image: 497 x 373 pixels
For more on resolution, sizes and other networks check out the full report made over at MakeaWebsitehub.com