Screen Size Calculator
Calculate TV and monitor screen dimensions from diagonal size. Find width, height, and area for any display size and aspect ratio. Compare 16:9, 21:9, 4:3 screens.
Enter Screen Diagonal & Aspect Ratio
TV & Monitor Size Comparison (16:9)
| Diagonal | Width | Height | Area | Size vs 55" |
|---|---|---|---|---|
| 24" | 20.9" | 11.8" | 247 in² | 19% |
| 27" | 23.5" | 13.2" | 311 in² | 24% |
| 32" | 27.9" | 15.7" | 437 in² | 34% |
| 43" | 37.5" | 21.1" | 790 in² | 61% |
| 50" | 43.6" | 24.5" | 1068 in² | 83% |
| 55" | 47.9" | 27.0" | 1293 in² | 100% |
| 65" | 56.7" | 31.9" | 1807 in² | 140% |
| 75" | 65.4" | 36.8" | 2405 in² | 186% |
| 85" | 74.1" | 41.7" | 3088 in² | 239% |
How to Calculate Screen Dimensions
The Math Behind Screen Sizes
TV and monitor sizes are measured diagonally, but you often need to know the actual width and height to fit a screen in your space. Using the diagonal measurement and aspect ratio, we can calculate the exact dimensions.
The Formulas
For a 16:9 aspect ratio:
Width = Diagonal × 0.872Height = Diagonal × 0.49General formula:
Width = Diagonal ÷ √(1 + (H/W)²)Example: 55" TV Dimensions
A 55" TV with 16:9 aspect ratio:
• Width = 55 × 0.872 = 47.9 inches (121.7 cm)
• Height = 55 × 0.49 = 27.0 inches (68.6 cm)
• Screen Area = 47.9 × 27.0 = 1,293 square inches
TV Size Buying Guide
32" - 43" TVs
Best for bedrooms, kitchens, or small apartments. Viewing distance: 4-6 feet.
50" - 55" TVs
Most popular size for living rooms. Viewing distance: 6-9 feet. Great balance of size and value.
65" - 75" TVs
Ideal for home theaters and large rooms. Viewing distance: 8-12 feet. Immersive experience.
85"+ TVs
Premium home cinema experience. Viewing distance: 10-15 feet. Consider wall mounting.
Frequently Asked Questions
How wide is a 55 inch TV?
A 55-inch 16:9 TV is approximately 47.9 inches (121.7 cm) wide and 27.0 inches (68.6 cm) tall. The bezel adds about 0.5-1 inch to each side, so total width is typically around 49-50 inches.
How is TV screen size measured?
TV size is measured diagonally from one corner to the opposite corner of the screen (not including the bezel/frame). This is an industry standard that dates back to the early days of CRT televisions.
What's the difference between a 55" and 65" TV?
A 65" TV is about 40% larger in screen area than a 55" TV, not just 18% (10/55). The 65" has 1,807 sq inches vs 1,293 sq inches for the 55". It's about 9 inches wider and 5 inches taller.
Will a 65 inch TV fit in my space?
A 65" 16:9 TV is approximately 56.7" (144 cm) wide and 31.9" (81 cm) tall. Make sure your TV stand or wall space is at least 58-60 inches wide to accommodate the TV plus bezel.
How do ultrawide monitors compare to regular monitors?
A 34" ultrawide (21:9) has similar height to a 27" standard (16:9) monitor but is significantly wider. The 34" ultrawide is 31.3" wide vs 23.5" for the 27" standard—about 33% more horizontal space.
Why don't diagonal inches represent actual viewing area?
Diagonal measurement can be misleading because screen area grows faster than the diagonal. A 65" TV has 40% more viewing area than a 55" TV, even though it's only 18% larger diagonally. Always compare square inches for true size comparison.
Related Calculators
Dimensions shown are for the screen only and do not include bezels or frames. Actual TV/monitor dimensions may vary by manufacturer.