Calculate screen dimensions, aspect ratios, and pixel density for TVs, monitors, and devices
55-inch display with 16:9 aspect ratio
HDTV, YouTube
Most modern content
Computer monitors
Productivity work
Classic TV/monitors
Older content
Ultrawide monitors
Cinematic movies
Modern smartphones
Taller screens
Surface tablets
Photography
Screen size is always measured diagonally from corner to corner, not width or height. This measurement dates back to the early days of cathode ray tube (CRT) televisions, where the diagonal measurement represented the viewable area of the circular tube.
Aspect ratio is the proportional relationship between width and height, expressed as two numbers separated by a colon (width:height). This ratio determines the shape of your screen and affects what content looks best.
16:9 (1.78:1) - The current standard for HDTVs, computer monitors, and streaming content. This "widescreen" format provides an immersive viewing experience for movies and TV shows.
16:10 (1.6:1) - Popular for computer monitors, especially for productivity work. The extra vertical space is useful for document editing, web browsing, and programming.
4:3 (1.33:1) - The classic television and early computer monitor format. Still used for some security cameras and industrial applications due to its square-like shape.
21:9 (2.33:1) - Ultrawide monitors that match many movie aspect ratios. Excellent for gaming, video editing, and multitasking with multiple windows.
18:9 and 19.5:9 - Modern smartphone aspect ratios that provide more screen real estate while keeping devices narrow enough to hold comfortably.
Pixels Per Inch (PPI) measures how densely packed the pixels are on a display. Higher PPI means sharper, more detailed images. This is particularly important for devices you view up close.
The ideal viewing distance depends on screen size and resolution. For HDTVs, the general rule is to sit 1.5-2.5 times the diagonal screen size away. For 4K TVs, you can sit closer (1-1.5x) to appreciate the extra detail.
TV Shopping: Consider your room size and seating distance. A 65" TV might seem impressive in the store but could be overwhelming in a small room.
Monitor Selection: For productivity, prioritize resolution and screen real estate over just size. A 27" 1440p monitor often provides better value than a 32" 1080p monitor.
Mobile Devices: Screen size affects portability. Larger phones offer better media consumption but may be difficult to use one-handed.
LCD/LED: Most common for monitors and TVs. LED refers to the backlight technology, not the display panel itself.
OLED: Self-lit pixels provide perfect blacks and infinite contrast. Common in high-end TVs and smartphones.
QLED: Samsung's quantum dot technology that enhances color reproduction in LCD displays.
40-50": Small rooms
55-65": Medium rooms
70-85": Large rooms
Consider 4K for 50"+
24": 1080p budget
27": 1440p sweet spot
32": 4K or ultrawide
Bigger needs higher resolution
16:9: General use, gaming
16:10: Productivity
21:9: Gaming, video editing
4:3: Legacy, industrial
HD: 1280×720
Full HD: 1920×1080
QHD: 2560×1440
4K UHD: 3840×2160
Measure First: Always measure your space and consider viewing distance before buying. Use this calculator to determine what size will work best.
Resolution Matters: For screens larger than 32", consider 4K resolution to maintain image sharpness. For smaller screens, 1080p or 1440p may be sufficient.
Refresh Rate: For gaming, look for 120Hz or higher. For general use, 60Hz is adequate.