MacBook Air 13 M4 vs MacBook Air 15 M4
A side-by-side readout for screen size.
Understanding screen size
Screen size is a numeric spec measured in ". On this metric, higher values are generally better, but returns diminish past category-typical thresholds — going from a low value to a mid value usually matters far more than going from a mid value to a high one. When comparing two products, focus on the percentage gap rather than the raw delta: a 200-unit lead means something very different at the low end of the range than at the high end. Pay attention to the unit, too — manufacturers sometimes quote peak or burst figures that are not sustained in real-world use. Cross-check the published number against independent measurements where possible, especially for performance and battery claims. Finally, remember that a single spec rarely tells the whole story; the Mars Score weighs screen size together with the rest of the spec sheet so one outlier doesn't distort the verdict.
This matchupMacBook Air 15 M4's 15.3" is roughly 13% higher than MacBook Air 13 M4's 13.6" (a 1.7" gap). Whether that gap is noticeable depends on workload — small percentage gaps rarely change day-to-day experience, while gaps of 20% or more usually do.
Other specs on this comparison
See the full Laptops category for all products ranked by Mars Score.