Screen Size & PPI Calculator - TV, Monitor, Phone & Projector

Calculate screen dimensions, PPI, viewing distance, and throw distance for TV, monitor, laptop, phone, tablet & projector.

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Monitor Size Calculator

Calculate dimensions, resolution & PPI

Width

23.53in

Height

13.24in

PPI

109

Area

312in²

Pixels

3.7MP

Pitch

0.23mm

Screen Visualization

How Screen Size Calculation Works

1

Enter Diagonal Size

Input your screen's diagonal measurement in inches or centimeters.

2

Select Aspect Ratio

Choose your display's aspect ratio (16:9, 16:10, 4:3, etc.).

3

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

Frequently Asked Questions

How do I calculate screen size from diagonal?
To calculate screen size from diagonal, you need the aspect ratio. Our calculator uses the Pythagorean theorem 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. Desktop monitors typically have 90-110 PPI, while smartphones have 300-500 PPI.
What is the most common aspect ratio?
16:9 is the most common aspect ratio for monitors and TVs, used for HD, Full HD, and 4K content.
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 to determine the optimal viewing distance based on your room size.
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). The comfortable range is 4.6-11.5 feet. HD TVs require slightly more distance.
What is projector throw distance?
Throw distance is how far the projector must be from the screen. It's calculated by multiplying screen width by the projector's throw ratio (typically 1.5 for standard projectors).
What is the difference between 4K and 1080p viewing distance?
With 4K TVs, you can sit closer without seeing pixels - about 1.0x the screen diagonal. 1080p TVs need 1.5-2.0x the diagonal for comfortable viewing.

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