Desktop display size
336x280 — Large Rectangle
Also called Large MPU.
- Width
- 336px
- Height
- 280px
- Aspect ratio
- 6:5
- Area
- 94,080px²
Actual size
Rendered at true pixel dimensions. On a narrow screen it scales down to fit.
Where it runs
In-article or sidebar, in the same positions that take a 300x250.
Why it is used
A slightly larger sibling of the medium rectangle, offering about 25% more area in the same position. Where a publisher's layout accommodates it, it typically earns a higher CPM than 300x250 for the same placement.
What to watch for
336 pixels does not fit inside a 320-pixel phone viewport, so unlike 300x250 it is not a safe universal size. Demand is also thinner, so a slot that accepts both sizes will usually fill more often than one restricted to 336x280.
File weight for standard display is commonly specified at around 150 KB initial load, but publisher specs vary and the figure that governs is always the one written into the insertion order. Check it before trafficking rather than after a creative is rejected.
Related sizes
Dimensions follow IAB Tech Lab display guidelines. Placement and performance guidance is practitioner knowledge, last verified July 2026.