Facebook Cover Photo Size

Read the help page closely and the sentence containing 851 × 315 is a claim about weight, not about shape: it sits alongside a colour space and a 100 kilobyte budget in advice about loading fastest. A 16:9 ratio is named separately, and a 2.4:1 ratio is named for mobile. Three figures, two of them about the container and one about the file.

That matters because the shapes are not compatible. An 851 × 315 image works out at about 2.7:1, which is wider than either named ratio. Filling a 16:9 frame with it means the frame is relatively taller, so the image scales up until it covers and the surplus width is discarded. Roughly a third of the width falls outside.

Once the frame is fixed at 16:9 the arithmetic is the same unit method used for any widescreen image. The only extra step is deciding which corner is expendable.

1. Choose 16:9, the desktop frame, as the shape to build at.
2. Pick a canvas large enough to survive a large display — 1920 px wide is a comfortable choice.
3. Divide the width by 16: 1920 ÷ 16 = 120 px per unit.
4. Multiply by 9 for the height: 120 × 9 = 1080 px, giving a 1920 × 1080 canvas.
5. Place the important content in the central band, clear of the bottom-left corner, then export under 100 KB.

Worked example

A designer builds an 851 × 315 cover because that is the number they found first. The logo is placed at the right-hand end. On a computer the 16:9 frame scales the image up to cover it, keeps the left edge because Facebook says the cover left-aligns, and discards roughly the rightmost third of the width — which is where the logo was. Building at 1920 × 1080 and letting Facebook reduce the file instead would have kept every element, at a smaller file weight.

Build at 16:9. It is the taller of the two published frames, and filling a 16:9 container exactly means the desktop view needs no crop at all. On a phone the 2.4:1 container is relatively wider, so it keeps the full width and trims the height instead — an ordinary top-and-bottom crop, the same behaviour as any banner.

The reverse does not work. A 2.4:1 file has no picture above or below the band a 16:9 frame wants, so something has to be invented or the image is pushed off its own edges. Facebook does not publish where the mobile trim falls, so assume the centre survives and the extremes do not.

• Keep the logo, the name and any wording in the central band, and let the left and right edges be background.
• Leave the bottom left corner clear. On a phone the Page's profile picture is drawn over it.
• Do not put a phone number, an address or a call to action near any edge; those are the elements that look careless when they go.
• Export a JPEG under 100 KB if loading speed matters, and check both the desktop and mobile previews before publishing.

A Facebook cover and a LinkedIn banner are both wide profile strips, but LinkedIn publishes one ratio for the whole surface while Facebook publishes two frames for one image. That extra frame is what makes the cover harder to get right.

• Instagram: Story size
• YouTube: Thumbnail size
• X: Header size
• Pinterest: Pin size
• LinkedIn: Profile banner size
• TikTok: Video size
• Instagram: Feed post size
• YouTube: Channel banner size
• X: Post image size

Every size here is one placement on one platform. The platform sizes index lists the rest, and each ratio guide explains the maths behind the shape itself.