Ad image size and aspect ratio calculator

Check how an image fits a square, portrait or vertical canvas before you rebuild the composition or export it.

Free to use. No account required.

Enter your numbers

The prefilled numbers are an example. Replace them with your own inputs.

Source width (pixels)

Use the original image dimensions.

Source height (pixels)

No image upload is needed.

Target canvas

Your canvas plan

Source aspect ratio: 300:157; Source width:height reduced to its simplest whole-number ratio
Target canvas: 1080 × 1350 px; Portrait · 4:5
Fit without cropping: 1080 × 565 px; Scale the whole source inside the target; unused canvas remains
Source area cropped to fill: 58.13%; 1 − target area ÷ scaled source area
Scale required to fill: 2.15×; Upscaling required; check source sharpness

How to use the result.

By IG Ad Library · Updated October 23, 2026. Calculations run in your browser.

Aspect ratio describes shape

Reduce width:height by their greatest common divisor to get the exact ratio. A 1080 × 1350 canvas is 4:5; a 1080 × 1920 canvas is 9:16. Resolution and shape are separate: the same ratio can have many pixel dimensions.

Fit and fill solve different problems

Fit preserves the whole image and leaves unused canvas when the shapes differ. Fill covers the canvas and crops part of the source. The crop estimate measures area removed, not whether a headline, face or product will survive the crop.

Recompose important content

Square 1080 × 1080, portrait 1080 × 1350 and vertical 1080 × 1920 are planning canvases here. Check the current placement specifications and preview overlays before publishing. Keep key copy and products away from interface overlays; this calculator does not certify placement eligibility.

Worked example

A 1080 × 1350 source fits the portrait canvas exactly. Filling a square with that source crops 20% of its area; fitting it instead preserves the whole image and leaves space on the sides.

Common questions.

Does this resize or export my image?

This free tool calculates dimensions and crop tradeoffs without uploading a file. Use Creator to edit a composition and export finished artwork.

Does a larger export improve a small source?

Upscaling adds pixels without recovering missing detail. If the tool indicates an upscale, inspect the output at its intended display size and use a higher-resolution source when possible.

Apply it to a creative reference.

Study the opening, promise and evidence in a real ad before deciding what to change.