Physical Size (96 DPI)
inches
20 x 11.25
centimeters
50.8 x 28.58
millimeters
508 x 285.8
Estimated File Size (24-bit)
Uncompressed (BMP)
5.9 MB
JPEG (estimated)
608 KB
PNG (estimated)
2 MB
Total Pixels
2,073,600 pixels (2.07 megapixels)
Calculators
Image Size Calculator: Find Dimensions for Print and Web
Image file size in bytes equals width x height x color depth / 8. A 3000x2000 pixel image at 24-bit color is approximately 18 MB uncompressed. JPEG compression typically reduces this by 90%.
Calculate image size in pixels, inches, or cm at any DPI. Find optimal dimensions for print and web. Estimate file size from resolution and color depth.
Image Size Calculator: Find Dimensions for Print and Web
Image file size in bytes equals width x height x color depth / 8. A 3000x2000 pixel image at 24-bit color is approximately 18 MB uncompressed. JPEG compression typically reduces this by 90%.
Calculate image size in pixels, inches, or cm at any DPI. Find optimal dimensions for print and web. Estimate file size from resolution and color depth.
Understanding Image Size
Image size encompasses both the pixel dimensions (digital size) and the physical dimensions (print size). The relationship between these depends on DPI - how many pixels are packed into each inch of output.
Physical Size Formula
Size in inches = Pixels / DPI
To convert to centimeters, multiply inches by 2.54. To convert to millimeters, multiply centimeters by 10.
File Size Estimation
- Uncompressed: Width x Height x (Bit Depth / 8) bytes. A 1920x1080 24-bit image is about 5.9 MB uncompressed.
- JPEG: Typically 1/10 to 1/20 of uncompressed size, depending on quality setting and image complexity.
- PNG: Typically 1/3 to 1/2 of uncompressed size for photos; much smaller for graphics with solid colors.
Common Image Dimensions
- Web banner: 1920x600 pixels at 72 DPI.
- Social media post: 1080x1080 pixels (Instagram) or 1200x630 pixels (Facebook).
- Print photo (4x6): 1200x1800 pixels at 300 DPI.
- Print poster (24x36): 7200x10800 pixels at 300 DPI.
Practical Quality Notes for Image Size Calculator
This calculator is most helpful when the result is tied to a real workflow, not treated as a loose number. For Image Size Calculator, verify the target output size, image pixel dimensions, aspect ratio, compression level, and intended viewing distance. That context prevents the common mistake of copying a pixel value into a print, web, or CSS workflow where the reference size is different.
Image Size Calculator should be checked with the formula, a realistic example, and the actual output requirement before you export or publish. If the number looks unexpectedly large or small, check the unit direction first, then check the DPI, base font size, viewport width, or physical measurement that controls the calculation.
A good review pass for Image Size Calculator is simple: calculate once, compare against a known example, and preview the final output at the size people will actually see. Image file size in bytes equals width x height x color depth / 8. A 3000x2000 pixel image at 24-bit color is approximately 18 MB uncompressed. JPEG compression typically reduces this by 90%.
Checks Before You Use the Result
- Confirm that Image Size Calculator is using the same input unit your source file or design brief uses.
- Save the DPI, viewport, or font-size setting next to the final Image Size Calculator value so another person can reproduce it.
- Preview the Image Size Calculator output on the target medium before sending it to print, publishing it, or adding it to CSS.
- Recalculate Image Size Calculator after resizing, cropping, changing aspect ratio, or changing the root font-size or viewport assumption.
When the Number Needs a Second Look
Recheck the result if the project moves from screen to print, from desktop to mobile, from one social platform placement to another, or from a draft export to a production file. Small context changes can make a correct Image Size Calculator answer wrong for the final job.
Sources
Reference Sources
These external references support the page's conversion formulas, resolution guidance, and unit explanations.
w3.org
W3C: CSS Values and Units Module Level 4
Specification covering absolute lengths and resolution units such as px, in, cm, mm, pt, and dpi.
Visit source
developer.mozilla.org
MDN: CSS values and units
Reference guide for CSS measurement units and how browsers interpret physical and relative sizes.
Visit source
developer.mozilla.org
MDN: <resolution>
Reference for resolution units including dpi, dppx, and dpcm used in screen and print discussions.
Visit source
developer.mozilla.org
MDN: image-resolution
Explains how raster image resolution metadata interacts with CSS and print-oriented image workflows.
Visit source
Frequently Asked Questions
For uncompressed images: file size = width x height x color depth / 8. A 1920x1080 24-bit (RGB) image = 1920 x 1080 x 3 bytes = 6.2 MB. JPEG compression typically reduces this to 0.5-2 MB depending on quality setting.
At 300 DPI: about 13.3 x 10 inches (a 12MP sensor delivers roughly 4000x3000 pixels). At 150 DPI: about 26.7 x 20 inches -- suitable for large posters.
Divide the pixel dimensions by the DPI. For example, a 1920x1080 image at 300 DPI is 6.4 x 3.6 inches. At 96 DPI (screen), the same image is 20 x 11.25 inches.
The uncompressed size is exact based on pixel count and bit depth. JPEG and PNG estimates are approximations - actual file size depends on image complexity, compression settings, and content. Simple images compress more than detailed photos.
Bit depth determines how many bits store each pixel. 8-bit stores 256 shades (grayscale), 24-bit stores 16.7 million colors (RGB), and 32-bit adds transparency (RGBA). Higher bit depth means larger file sizes.