Image Size Calculator
Calculate dimensions, aspect ratios, and file sizes for digital images
Disclaimer: This tool provides estimates for image dimensions and file sizes. Actual file sizes may vary based on compression, format, and image content. For print projects, always consult with your printer for exact specifications.
Tip: Use this calculator to optimize images for web, social media, or print projects.
Original Image
Target Settings
Calculation Results
Dimensions
File Information
Common Use Cases
Understanding Image Dimensions & Sizes
Pixel Dimensions
Pixel dimensions measure the width and height of an image in pixels. This determines how much detail your image contains and how large it can be displayed on screens without appearing pixelated.
Resolution (DPI/PPI)
Resolution determines how many pixels are printed per inch (DPI) or displayed per inch on screen (PPI). Higher resolution means more detail but larger file sizes.
"For web use, 72 PPI is standard, while print projects typically require 300 DPI or higher for quality results."
Optimizing Images for Different Platforms
Social Media
Each platform has ideal image dimensions. Facebook posts (1200×630), Instagram squares (1080×1080), and Twitter headers (1500×500) all have different requirements. Using the correct sizes ensures your images display properly without cropping or distortion.
Web Use
Balance quality with load times. For websites, aim for 72 PPI resolution and optimize file sizes (typically under 200KB for JPEGs). Use compression tools to reduce file size without noticeable quality loss.
Print Projects
Print requires higher resolution (300 DPI minimum). Calculate required pixel dimensions by multiplying print size (in inches) by DPI. For example, an 8×10 print at 300 DPI needs 2400×3000 pixels.
Pro Tip: When resizing images, always maintain the original aspect ratio to prevent distortion. Our calculator automatically preserves aspect ratio unless you specify a custom ratio.
Frequently Asked Questions
How do I calculate image file size?
File size depends on dimensions (total pixels), color depth, and compression. Our calculator estimates based on common compression ratios for each file format. Actual sizes may vary based on image content complexity.
What's the difference between DPI and PPI?
DPI (dots per inch) refers to printer resolution, while PPI (pixels per inch) refers to screen resolution. They're often used interchangeably, but technically DPI is for print output and PPI is for digital display.
How many megapixels do I need for quality prints?
For an 8×10 print at 300 DPI, you need about 7.2 megapixels (2400×3000 pixels). Larger prints or higher DPI requirements need more megapixels. Our calculator helps determine if your image has sufficient resolution.
Why does aspect ratio matter?
Aspect ratio (width:height proportion) determines how your image will fit different displays or frames. Changing it improperly can cause stretching or cropping. Common ratios include 4:3 (standard), 16:9 (widescreen), and 1:1 (square).
How can I reduce image file size without losing quality?
Use proper compression settings (85% quality for JPEGs), remove unnecessary metadata, consider modern formats like WebP, and resize to the exact dimensions needed rather than relying on HTML/CSS scaling.