What is the default effective resolution of the Macbook Air 2020

The Internet says that the Macbook Air's resolution is 2560x1600, and that its supported scaled resolutions are:

1. 1680 by 1050
2. 1440 by 900
3. 1024 by 640

But which of those supported scaled resolutions is the effective resolution of the Macbook by default? Or maybe it's not even listed. If you use the non-default scaled resolutions, they don't look quite right to my eyes, and so I want to know how small or large everything is. Most software doesn't factor in hardware pixels when choosing what size to display.

For example, the Macbook Pro 16-inch has a native 3072x1920 resolution, and its supported scaled resolutions are:

1. 2048 x 1280
2. 1792 x 1120
3. 1344 x 840
4. 1152 x 720

#2 is the effective resolution when running in default retina mode, giving the Macbook Pro a PPI of 132.08

By default, Mac Retina displays are always at scaled to 2x the 'actual' resolution. So a 2560 x 1600 display will be a "Hi-res" version of 1280 x 800.

I suspect that Apple's list of "supported scaled resolutions" does not include the default 2x Retina setting. This is backed up by the wording used on my 15" MBP:

2880 by 1800 pixels (Retina); scaled resolutions: 1920 by 1200, 1680 by 1050, 1280 by 800, and 1024 by 640 pixels

The Scaling options in System Preferences offer 5 options: four of them being the scaled sizes and the middle button being the default. (I'm hovering the mouse over the 2nd from left in the the image.)

The 16" MBP's default resolution is 1536 x 960 "Hi-res".

You are right that "most software doesn't factor in hardware pixels when choosing what size to display" - that's the job of the OS. MacOS's use of 2x scaling is designed to be the clearest.

If the non-default scaled resolutions don't look right to your eyes (understandably so), then just use the default.

Retina mode is to use multiple pixels for a virtual point. So the cleanest scaled resolution would be if you scaled the native resolution by a whole number. For my 15 inch version the native 2880x1800 should be scaled to 1440x900 giving 2x scaling and 4 pixels per point. This holds up as this resolution looks sharpest out of all the options offered.

The Air's 2560x1600 scaled at 2x would be 1280x800. But it isn't offered so your choices are:

• 1680x1050 is almost 1.5 perfectly
• 1440x900 is 1.7 repeating, and
• 1024x640 is 2.5 exactly.

The almost 1.5x scaling seems to be the best of the choices offered in terms of sharpness. But the text might be too small for some users. You can also try an app to switch to the 2560x1600 resolution, like RDM (Retina Display Manager).

To quickly assure yourself of the current logical resolution: Press CMD+Shift+4 to capture part of the screen, and the coordinates will be shown next to the cursor. Move the cursor to the lower right corner to see the resolution (you will have to add one to each coordinate).

Alternatively, in this same mode, drag from one corner to the opposite one to select the whole screen, and the size will display in full, no addition required.