Free Screen Size Calculator - TV, Monitor, Phone & Projector
Calculate display dimensions, viewing distance, PPI, and throw distance instantly. Perfect for choosing the right TV, monitor, laptop, phone, or projector.
Screen Size Calculator
Calculate display dimensions, PPI, and more
Width
23.53in
Height
13.24in
PPI
109
Area
312in²
Pixels
3.7MP
Pitch
0.23mm
Screen Visualization
Screen = 6.8x card
Popular Screen Size Comparisons
Compare screen sizes visually. See how different devices stack up against each other.
How Screen Size Calculation Works
Enter Diagonal Size
Input your screen's diagonal measurement in inches or centimeters.
Select Aspect Ratio
Choose your display's aspect ratio (16:9, 16:10, 4:3, etc.).
Get Instant Results
See width, height, area, PPI, and total megapixels instantly.
The Math Behind It
Screen dimensions are calculated using the Pythagorean theorem:
Height = diagonal / sqrt(1 + (w/h)^2)
Width = Height * (w/h)
PPI = sqrt(px_width^2 + px_height^2) / diagonal
Common Screen Sizes Reference
| Device Type | Diagonal | Resolution | Typical PPI |
|---|---|---|---|
| Smartphone | 5.5" - 6.7" | 1080 x 2400 | 380 - 450 |
| Tablet | 10" - 12.9" | 2560 x 1600 | 220 - 280 |
| Laptop | 13" - 17" | 1920 x 1080 | 120 - 170 |
| Desktop Monitor | 24" - 32" | 2560 x 1440 | 90 - 120 |
| 4K TV | 50" - 75" | 3840 x 2160 | 55 - 90 |
Frequently Asked Questions
How do I calculate screen size from diagonal?
To calculate screen size from diagonal, you need the aspect ratio (e.g., 16:9). The formula uses the Pythagorean theorem. Our calculator does this automatically - just enter your diagonal size and aspect ratio.
What is PPI and why does it matter?
PPI (Pixels Per Inch) measures pixel density. Higher PPI means sharper images and text. Desktop monitors typically have 90-110 PPI, while smartphones need 300-500 PPI because they're viewed up close.
What is the most common aspect ratio?
16:9 is the most common for monitors and TVs. Other popular ratios: 16:10 (productivity), 21:9 (ultrawide), 4:3 (legacy), and 32:9 (super ultrawide).
How do I measure my screen size?
Measure diagonally from one corner to the opposite corner of the visible display area (not the bezel). Use a tape measure from bottom-left to top-right.
What screen size should I buy for my desk?
- 24" (1080p) - Limited space, ~2ft distance
- 27" (1440p) - Sweet spot, 2-3ft distance
- 32" (4K) - Productivity, 2.5-4ft distance
- 34" Ultrawide - Multitasking
What size TV should I buy for my living room?
For a living room with 8-12 feet viewing distance, a 55-65 inch 4K TV is ideal. Use our TV mode calculator above to determine the optimal viewing distance based on your specific room size and seating arrangement.
How far should I sit from a 55 inch TV?
For a 55 inch 4K TV, the optimal viewing distance is 7.3 feet (2.2m) based on SMPTE standards. The comfortable range is 4.6-11.5 feet. For HD (1080p) TVs, you should sit slightly farther. Switch to TV mode in our calculator for personalized recommendations.
What is projector throw distance?
Throw distance is how far the projector must be placed from the screen to achieve your desired screen size. It's calculated by multiplying screen width by the projector's throw ratio (typically 1.5 for standard projectors, 0.5 for short-throw). Our Projector mode calculates this automatically.
What's the difference between 4K and 1080p viewing distance?
With 4K (UHD) TVs, you can sit closer without seeing individual pixels - about 1.0x the screen diagonal. For 1080p (Full HD) TVs, you need 1.5-2.0x the diagonal for comfortable viewing. This is why 4K is better for larger screens in smaller rooms.
Find Your Perfect Screen Size
Whether you're shopping for a new TV, upgrading your monitor, or comparing phone displays - use our calculator to make an informed decision.
Calculate Your Screen Size Now