Resize by dimensions or scale by percentage (25%, 50%, 200%, 2x). Maintain aspect ratios automatically.
Input your original image dimensions or upload an image
Select by width, height, percentage, or use presets
Enter desired size or pick from quick presets
See new dimensions, aspect ratio, and file size
Set the desired width, and the height is automatically calculated to maintain the aspect ratio.
Best for: Fixed-width layouts, blog posts, responsive designs
Set the desired height, and the width is automatically calculated to maintain the aspect ratio.
Best for: Fixed-height containers, sidebars, thumbnails
Scale the image by a percentage (25%, 50%, 200%) or multiplier (0.5x, 2x, 3x). Perfect for quick, proportional resizing while maintaining aspect ratio automatically.
Best for: Quick scaling, file size reduction, consistent sizing, batch processing
Image is scaled to fit within maximum width and height while maintaining aspect ratio. Never exceeds limits.
Best for: Container constraints, responsive images, galleries
Set exact width and height independently. Can distort the image if aspect ratio is not maintained.
Best for: Specific requirements, thumbnails, crops
Image scaling refers to proportionally resizing an image using a percentage or multiplier. Unlike fixed dimension resizing, scaling maintains the exact proportions of your image while making it larger or smaller. This is the most common method for resizing images without distortion.
Example:
Original: 1920 × 1080 px
Scale: 50% (0.5x)
Result: 960 × 540 px
To calculate scale percentage: (New Size ÷ Original Size) × 100. For example, resizing from 1920px to 960px width: (960 ÷ 1920) × 100 = 50% scale. Our calculator shows this automatically - just select "By Percentage" mode and choose from quick presets (25%, 50%, 75%, 200%) or enter a custom value.
Resizing can mean changing to specific dimensions (like 800×600px), which might alter proportions. Scaling specifically means proportional resizing using a multiplier or percentage (like 50% or 2x), which always maintains the original aspect ratio. Scaling is safer for avoiding distortion.
2x scale (or 200%) means doubling both width and height, making the image 4 times larger in total area. A 1920×1080px image at 2x becomes 3840×2160px. This is commonly used for Retina displays where pixel density is double. Note: Upscaling reduces quality, so start with high-resolution originals.
When you resize an image, you're changing the number of pixels. Downscaling (making smaller) is generally safe and maintains quality by removing excess pixels. Upscaling (making larger) can result in pixelation or blurriness because you're interpolating new pixels from existing ones. Always keep original high-res versions.
Yes, in most cases. Maintaining aspect ratio prevents distortion and keeps your image looking natural. Only break aspect ratio when you specifically need an exact size (like a profile picture) and are prepared to crop or accept some distortion. Use our "Custom Dimensions" mode for this.
Scaling to 50% (half dimensions) typically reduces file size by approximately 75%. This is because you're reducing total pixels by 75% (width × height both halved = 25% of original pixels). Actual reduction varies by image complexity and compression, but it's a reliable way to dramatically reduce file sizes for web delivery.
Our calculator provides estimates based on typical compression rates. Actual file sizes depend on image complexity - photos with lots of detail compress less than simple graphics. Use the estimates as a guide, but test with actual files for precise requirements. JPEG quality settings significantly affect final size.
JPEG is best for photographs and offers smaller file sizes with slight quality loss (adjustable). PNG is best for graphics, logos, or images with transparency, but creates larger files. For most photo resizing, JPEG at 80-85% quality is ideal. PNG is better for screenshots and diagrams.
Traditional upscaling always results in some quality loss. However, modern AI-powered upscaling tools can produce better results than simple interpolation. For best results, always start with the highest resolution source image possible and avoid upscaling beyond 150-200% of the original size. Consider AI upscalers for critical work.
For web optimization, aim to match your actual display size. A hero image displayed at 1200px wide doesn't need to be 4000px. Common practice: 50-75% reduction for web use maintains quality while significantly reducing load time (better page speed = better SEO). Consider creating multiple sizes for responsive design (srcset).
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