Image File Size Estimator

Estimate file size from resolution, bit depth, and compression format. Compare RAW, TIFF, JPEG at various quality levels, PNG, BMP, and WebP.

Image Parameters

Uncompressed Size = Width × Height × (Bit Depth ÷ 8) × Channels

Image Width

Image Height

Bit Depth (per channel)

Color Channels

Common presets:

Format Reference

Format	Compression	Bit Depth	Typical Use
RAW	Lossless (sensor data)	12–14 bit	Professional photography, maximum editing flexibility
TIFF	None or lossless (LZW)	8–32 bit	Archival, print production, lossless editing
PNG	Lossless (DEFLATE)	8–16 bit	Web graphics, screenshots, transparency
BMP	None	8–32 bit	Uncompressed bitmap, legacy applications
JPEG 100%	Lossy (minimal)	8 bit	High-quality archiving, near-lossless
JPEG 80%	Lossy (moderate)	8 bit	General photography, good quality-to-size ratio
JPEG 60%	Lossy (noticeable)	8 bit	Web publishing, social media
JPEG 20%	Lossy (heavy)	8 bit	Thumbnails, previews, low-bandwidth
WebP	Lossy or lossless	8 bit	Modern web delivery, smaller than JPEG

How It Works

Uncompressed Image Size

The raw, uncompressed size of an image is calculated as:

Size (bytes) = Width × Height × Channels × (Bit Depth ÷ 8)

For example, a 6000×4000 pixel image at 14-bit RGB has 24 million pixels, each storing 3 channels at 14 bits = 5.25 bytes per pixel, totaling about 126 MB uncompressed.

Compression Ratios

Different formats apply different levels of compression to reduce file size:

RAW: Camera sensor data with light lossless compression. Typically 50–70% of the theoretical uncompressed sensor data size, depending on the camera manufacturer's compression algorithm.
TIFF (uncompressed): Stores the full pixel data without compression, 100% of the calculated uncompressed size.
TIFF (LZW): Lossless compression reduces size to roughly 50–70% of uncompressed, depending on image content.
PNG: Lossless DEFLATE compression typically achieves 30–60% of uncompressed size for photographic content.
BMP: No compression, 100% of uncompressed size plus a small header.
JPEG: Lossy DCT-based compression. Quality 100% yields roughly 1:4 ratio, quality 80% roughly 1:10, quality 60% roughly 1:18, quality 20% roughly 1:40.
WebP: Modern format with better compression than JPEG. Lossy WebP at equivalent quality is roughly 25–35% smaller than JPEG.

Bit Depth Explained

Bit depth determines how many distinct values each color channel can represent:

8-bit: 256 levels per channel (16.7 million colors for RGB). Standard for displays and JPEG.
10-bit: 1,024 levels. Used in video and some displays.
12-bit: 4,096 levels. Common in entry-level RAW files.
14-bit: 16,384 levels. Standard for professional camera RAW files.
16-bit: 65,536 levels. Used in TIFF for high-quality editing.
32-bit float: HDR imaging, scientific data, and compositing.

Important Notes

These are estimates. Actual file sizes vary based on image content — images with more detail or noise compress less efficiently.
RAW file sizes depend heavily on the camera manufacturer's proprietary format and compression.
JPEG compression efficiency varies with image complexity — smooth gradients compress better than detailed textures.
Metadata (EXIF, ICC profiles, XMP) adds a small overhead not included in these estimates.

Related Utils

Print Size Calculator DOF Calculator Image Resize Image Compress Image Metadata

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