OS Details

MacBook Pro 2018 (13 inch) has been launched in Mid 2018.
MacBook Pro 2018 (13 inch) have macOS Mojave

Device Size

MacBook Pro 2018 screen size is 13.3 inch screen . Physical dimensions for MacBook Pro 2018 (13 inch) device is 11.97 x 0.59 x 8.36 INCH or ( 30.41 x 1.49 x 21.24 CM).

Displaying of Units are in this order "Width x Height x Depth"

Screen Pixel Density and CSS Pixel Ratio

"Pixel" is smallest unit/element of any display.

The total number of pixels that fit into an inch is referred to as "Screen Density" or "Pixel Density" and it measured as "Pixels Per Inch".
Pixel Desnsity have limits to display Pixels Per Inch depends on different screen sizes. When number of pixels per inch increases than it's screen-size limit, the Display resolution will increase but actual device width/height in pixels remain same. Actual device pixels are known as Device Independent Pixels or CSS Pixel Ratio.

MacBook Pro 2018 (13 inch) resolution is 2560 x 1600 ^PX with ~ 227 pixel desnsity.
MacBook Pro 2018 (13 inch) viewport size is 1280 x 800 ^PX with ~ 113 actual pixel density, which means it have 2 xhdpi display pixel density.

Screen Resolution and Viewport

The sum of pixels which are displaying on a device is called as "Screen Resolution". and sum of actual pixels of any device is reffered to as "Viewport".

MacBook Pro 2018 (13 inch) have 13.3" physical screen size with IPS technology and it's native resolution is 2560 x 1600 Pixels with approximately 227 PPI pixel density. MacBook Pro 2018 (13 inch) has viewport size 1280 x 800 Pixels and its pixel ratio is about 2.

MacBook Pro 2018 (13 inch) supports scaled lower resolutions listed below:
- 1680 x 1050
- 1440 x 900
- 1024 x 640

MacBook Pro 2018 (13 inch) built-in-display to support highly NATIVE resolutions upto 5K with use of thunderbolt or HDMI display devices. Here some list below:
- One display with 5120 x 2880 resolution at 60Hz
- Up to two displays with 4096 x 2304 resolution at 60H
- Up to two displays with 3840 x 2160 resolution at 60Hz

Thunderbolt 3 digital video output:
- Native DisplayPort output over USB‑C
- VGA, HDMI, and Thunderbolt 2 output supported using adapters (sold separately)

For better understanding screen actual sizes, viewport sizes, display resolution and about their density click here.

CSS Media Queries

MacBook Pro 2018 (13 inch) Media Queries (In terms of Mobile only)

@media only screen and (min-width: 1280px) and (max-width: 767px) { /* Your Styles... */ }

MacBook Pro 2018 (13 inch) Min-Width Media Queries

@media only screen and (min-width: 1280px) { /* Your Styles... */ }

MacBook Pro 2018 (13 inch) Min-Height Media Queries

@media only screen and (min-height: 800px) { /* Your Styles... */ }

MacBook Pro 2018 (13 inch) Landscape Media Queries

@media only screen and (min-width: 800px) and (orientation: landscape) { /* Your Styles... */ }

MacBook Pro 2018 (13 inch) Portrait Media Queries

@media only screen and (min-width: 1280px) and (orientation: portrait) { /* Your Styles... */ }

MacBook Pro 2018 (13 inch) Device Width Media Queries

@media only screen and (min-device-width: 1280px) and (orientation: portrait) { /* Your Styles... */ }
@media only screen and (min-device-width: 800px) and (orientation: landscape) { /* Your Styles... */ }

MacBook Pro 2018 (13 inch) Retina Media Queries

@media
  only screen and (-webkit-min-device-pixel-ratio: 2),
  only screen and (   min--moz-device-pixel-ratio: 2),
  only screen and (     -o-min-device-pixel-ratio: 2/1),
  only screen and (        min-device-pixel-ratio: 2),
  only screen and (                min-resolution: 227dpi),
  only screen and (                min-resolution: 2dppx) { 
    /* Retina styles here */
}
                                

Retina is actually based upon device pixel ratio. Devices mostly have 2x or 3x display so you can use general retina media queries to display high resolution content on all kind of devices. Retina 2x and Retina 3x media queries given below:

Retina 2x Media Query

@media
  only screen and (-webkit-min-device-pixel-ratio: 2),
  only screen and (   min--moz-device-pixel-ratio: 2),
  only screen and (     -o-min-device-pixel-ratio: 2/1),
  only screen and (        min-device-pixel-ratio: 2),
  only screen and (                min-resolution: 192dpi),
  only screen and (                min-resolution: 2dppx) { 
    /* Retina styles here */
}
                                

Retina 3x Media Query

@media
  only screen and (-webkit-min-device-pixel-ratio: 3),
  only screen and (   min--moz-device-pixel-ratio: 3),
  only screen and (     -o-min-device-pixel-ratio: 3/1),
  only screen and (        min-device-pixel-ratio: 3),
  only screen and (                min-resolution: 384dpi),
  only screen and (                min-resolution: 3dppx) { 
    /* Retina styles here */
}
                                

MacBook Pro 2018 (13 inch) Specifications

• Launch Date Mid 2018
• OS macOS High Sierra
• Physical Screen Size 13.3 INCH
• Resolution 2560 x 1600 PX
• Viewport Size 1280 x 800 PX
• Pixel Density 227 PPI
• Device-Independent Pixels 113 PPI
• Pixel Ratio 2 xhdpi
• Width 2560 PX
• Height 1600 PX
• Device Width 1280 PX
• Device Height 800 PX
• Dimensions 30.41 x 1.49 x 21.24 cm (11.97 x 0.59 x 8.36 in)
• Weight 1.37 kg - 3.02 Pounds