Display Resolution Calculator    Results =  PPI, Dot Pitch, Screen Width, and Screen Height

 

Horizontal pixels:   (such as 1280)
Vertical pixels:   (such as 800)
Diagonal size (inches):   (such as 15.4)
   

Pixels per Inch     PPI:  
Dot Pitch:  
Screen Width:  
Screen Height:  
 
PPI and Dot Pitch are interchangeable measurements of screen resolution, a primary factor controlling the size of objects on your screen. 


PPI is Pixels Per Inch, normally measured horizontally or vertically.
Dot Pitch is the spacing of pixels, measured in millimeters from pixel center to center.
 

  
  Examples  - The  Red  values display fonts too small for many users  
System Pixels           Diagonal  PPI   Dot Pitch
  		Screen Width Screen Height
Thinkpad T61 (14.1) 1024 x 768 14.1"    90.78     .28 mm   11.28" 8.46"
Thinkpad T500 (15.4) 1280 x 800 15.4"    98.02   .26 mm   13.06" 8.16"
Thinkpad T410s 1440 x 900 14"  121.29   .21 mm   11.87" 7.42"
Thinkpad T420s 1600 x 900 14"  131.13   .19 mm   12.20" 6.86"
Most 14" Ultrabooks 1366 x 768 14"  111.94   .23 mm   12.20" 6.86"
 

screen font too small
menus take up too much space
too much vertical scrolling

What's wrong with new notebook, laptop computers ?  (for some users)

 - text too small  -  screen too short  -  application workspaces don't fit on screen
 
Notebook manufacturers have drifted away from the needs of productivity users and baby-boomers/Seniors as they increasingly limit their offerings to Widescreen, high resolution displays.  New notebooks are designed for people who use their portable computers primarily for the casual consumption of media and email; not for those in the "working sector" like programmers, engineers, financial analysts, system administrators, designers, accountants or writers who need some vertical space in their display. 
 

There is nothing you can do to increase the height of a Wide Screen, but most applications such as Microsoft Office and all Web Browsers have a "ZOOM" feature to provide scaling of content within these applications. Zoom does not address size of System Interfaces or Application Menus. 

Regarding hyperopic users, the first two systems in the examples above have a PPI of less than 100 providing reasonable viewing for a senior, but systems like this have not been available since 2010. All new notebooks have a PPI of over 110 and many are a strain or nearly unusable for many users.


Countermeasures to address visibility problems you may have with a high screen resolution screen.

ZOOM   (Ctrl - ScrollWheel)
  The Zoom feature is perfect for scaling application content to the user's preference, but it does not scale application menus or any Windows Interface features.

There are 3 ways to set the Zoom level with most Web Browsers or any Microsoft Office application, but the easiest method is to use the Scroll Wheel on your mouse while holding down the Ctrl key.  Some applications remember your last Zoom setting from session to session.
 
Set Custom Test Size (DPI)     (Control Panel > Display > Set custom text size (DPI))
  In theory, this setting can address the scale of some application content plus Menus and the Windows interface but in fact is a poor compromise because many interfaces and menus do not display correctly with changes to this setting. For example, text may not fit in interface boxes or in drop-down menus, so changing the DPI is only a last resort if you can't see application and system interfaces.  If you try this, Windows has a preset of +125% which is a large increment. With a little digging you can find the place to add any % value you want.
 
Add an External Monitor - Extend your Desktop for under $150.00
  When using a notebook at your home or office, an attached monitor can provide more vertical and horizontal working space and provide a lower PPI than any new notebook computer.

Specific Recommendation:  Dell ST2220L
A 21.5" 1920x1080 monitor (ppi = 102.46) provides good vertical and horizontal working space and isn't unreasonably large to work as an extended desktop to a notebook computer.

The author tested 3 brands of sub $150.00 monitors with these specs. I expected the brands to be equal, but a Dell model had the best display quality between the units tested.  At the time of testing, a Dell ST2220L cost $120.00 on-sale at Micro-Center. 
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