Convert image dimensions into megapixels, the reduced aspect ratio (16:9, 4:3), the nearest common ratio, print sizes at 300 DPI, and uncompressed file sizes for B&W, grayscale, RGB, and RGBA images.
Overview
The Pixel & Aspect Ratio Converter takes image dimensions and returns the resolution, megapixel count, the reduced aspect ratio, the nearest standard ratio (16:9, 4:3, and so on), the print size at 300 DPI, and the uncompressed file size for common bit depths.
Common Use Cases
Calculating megapixels and aspect ratio for CCTV cameras
Checking whether a video or photo is 16:9, 4:3, or another standard
Estimating uncompressed image sizes for editing and storage
Working out print sizes at 300 DPI from pixel dimensions
Verifying resolution labels on camera listings
Choosing crop dimensions that keep a target aspect ratio
Estimating raw sensor capture sizes
How to Use
1
Type the width and height in pixels.
2
All results update instantly: megapixels, aspect ratio, common ratio, print size, and uncompressed sizes.
3
The aspect ratio is reduced by the greatest common divisor and then matched against common standards.
4
Use the Print button to export the result table.
Example Scenario
A 1920 × 1080 camera frame
Enter 1920 and 1080. The calculator reports 2.07 MP, a 16:9 aspect ratio, a 6.4 × 3.6 inch print at 300 DPI (16.26 × 9.14 cm), and an uncompressed RGB size of 6.22 MB.
Technical Notes
Megapixels are width × height ÷ 1,000,000. Common values: 1080p is 2.07 MP, 4K UHD is 8.29 MP, 8K is 33.18 MP.
The reduced ratio divides width and height by their greatest common divisor. The common-ratio match uses a small tolerance so near-standard ratios are detected.
Print size is pixels divided by DPI, then converted to centimeters. 300 DPI is the standard for sharp photo prints.
Uncompressed size is width × height × bits per pixel ÷ 8. Real formats like JPEG and H.264 are far smaller.
Common Mistakes
Thinking more pixels always means better quality regardless of lens and sensor
Treating decimal MP values as if they were exact binary figures
Assuming every image labeled 1080p is exactly 16:9
Confusing DPI (printing) with PPI (screens)
Frequently Asked Questions
2.07 megapixels at 16:9 aspect ratio. Uncompressed that is about 6.2 MB for a 24-bit RGB frame before compression.
At 300 DPI, an 8×10 inch print needs 2400 × 3000 pixels, or about 7.2 megapixels.
Divide width by height and reduce the pair by their greatest common divisor. The calculator does this for you and names the standard ratio if it matches.
DPI is dots per inch and describes printing; PPI is pixels per inch and describes screens. For print math, 300 DPI is the common standard.