The RAW File Size Calculator estimates the storage size of unprocessed camera RAW files based on sensor megapixels, bit depth, and the compression method used by the specific camera manufacturer. RAW files are the unprocessed sensor data captured by a digital camera before any in-camera JPEG processing is applied. Unlike JPEGs (which apply lossy compression and reduce data to approximately 8 bits per channel with 10:1 compression), RAW files preserve the full precision of the sensor's analog-to-digital conversion — typically 12, 14, or 16 bits per pixel per channel. This allows dramatically more post-processing flexibility: up to 4 additional stops of shadow recovery and highlight recovery compared to JPEG, noise reduction that operates on the raw sensor mosaic data rather than a processed image, and color grading latitude that produces smooth, artifact-free gradients even with heavy adjustments. RAW file size depends on: sensor megapixel count, bit depth (12-bit vs. 14-bit vs. 16-bit RAW), compression type (uncompressed, lossless compressed, lossy compressed, or manufacturer-specific variants), and the Bayer pattern or X-Trans mosaic structure used by the sensor. Major camera manufacturers use proprietary RAW formats: Canon (CR3, CR2), Nikon (NEF), Sony (ARW), Fujifilm (RAF), Olympus/OM System (ORF), Panasonic (RW2), Hasselblad (3FR), Phase One (IIQ), and DNG (open standard from Adobe). Understanding RAW file size helps photographers plan memory card capacity, hard drive storage, and backup strategies for shoots.
Uncompressed RAW Size (bytes) = Megapixels × 1,000,000 × (Bit Depth / 8) × 1.0 (Bayer, 1 channel per pixel) With Bayer debayering overhead: × 1.5 (approximate) Lossless Compressed RAW ≈ Uncompressed × 0.5–0.7 Manufacturer Compressed RAW ≈ Uncompressed × 0.4–0.6 File Size (MB) = Size (bytes) / 1,048,576 Memory Card Images = Card Capacity (MB) / Average RAW File Size (MB)
- 1Step 1: Determine sensor megapixels (use effective megapixels from the camera specification sheet).
- 2Step 2: Identify the bit depth of your camera's RAW format (typically 12-bit or 14-bit; check camera menu or spec sheet).
- 3Step 3: Calculate raw bytes: MP × 1,000,000 × (bit_depth / 8).
- 4Step 4: Apply Bayer overhead factor (~1.5× for standard Bayer sensors) to account for metadata, header, and thumbnail data embedded in the RAW file.
- 5Step 5: Apply compression ratio (lossless ≈ 0.6, lossy compressed ≈ 0.5, uncompressed = 1.0).
- 6Step 6: Divide by 1,048,576 for megabytes. Compare to manufacturer-stated file sizes for calibration.
Uncompressed 14-bit: 45M × 1.75 bytes × 1.5 (overhead) = 118 MB theoretical. Canon's lossless RAW compresses to ~45 MB; C-RAW (lossy) compresses to ~28–35 MB. Trade-off: C-RAW has slightly less shadow recovery vs. full RAW.
Nikon's lossless compressed NEF for the Z9 at 45.7 MP produces 50–60 MB files. At 120 fps high-speed burst, this generates approximately 7.2 GB per second — requiring fast CFexpress Type B cards.
Sony's compressed ARW for 61 MP captures: 61M × 1.75 bytes × overhead ≈ 160 MB uncompressed. Sony's compression achieves ~55–65 MB. A 256 GB CFexpress card holds approximately 3,800–4,500 RAW images.
Fujifilm's X-Trans sensor has a non-Bayer color filter array that creates larger RAW files relative to megapixel count because the X-Trans mosaic requires more complex demosaicing data. 40 MP X-Trans RAF files are larger than typical 40 MP Bayer sensor files.
Photographers planning memory card purchases before major shoots., representing an important application area for the Raw File Size in professional and analytical contexts where accurate raw file size calculations directly support informed decision-making, strategic planning, and performance optimization
Photo studios calculating storage infrastructure for client image archives., representing an important application area for the Raw File Size in professional and analytical contexts where accurate raw file size calculations directly support informed decision-making, strategic planning, and performance optimization
Print labs specifying minimum file size requirements for large-format output., representing an important application area for the Raw File Size in professional and analytical contexts where accurate raw file size calculations directly support informed decision-making, strategic planning, and performance optimization
Camera buyers understanding storage implications of different megapixel choices., representing an important application area for the Raw File Size in professional and analytical contexts where accurate raw file size calculations directly support informed decision-making, strategic planning, and performance optimization
Pixel Shift RAW files
{'title': 'Pixel Shift RAW files', 'body': 'Cameras with pixel-shift high-resolution modes (Olympus OM-1, Sony A7R V, Panasonic Lumix S5 II) capture multiple frames that are assembled into a single high-resolution RAW file. The resulting pixel-shift RAW is 4–16× larger than a single-frame RAW — a 20 MP sensor producing 80 MP pixel-shift output generates RAW files of approximately 150–200 MB per capture.'}
Cinema RAW formats
{'title': 'Cinema RAW formats', 'body': 'Cinema cameras use different RAW standards: Blackmagic RAW (BRAW) at various compression levels (3:1 to 12:1), ARRIRAW (lossless, very large), Sony Cinema RAW Light (compressed), Canon Cinema RAW Light (compressed). These formats are optimized for video workflows with different compression philosophies than still camera RAW formats.'}
When using the Raw File Size for comparative raw file size analysis across
When using the Raw File Size for comparative raw file size analysis across scenarios, consistent input measurement methodology is essential. Variations in how raw file size inputs are measured, estimated, or rounded introduce systematic biases compounding through the calculation. For meaningful raw file size comparisons, establish standardized measurement protocols, document assumptions, and consider whether result differences reflect genuine variations or measurement artifacts. Cross-validation against independent data sources strengthens confidence in comparative findings.
| Camera | Megapixels | Bit Depth | RAW Format | Typical File Size |
|---|---|---|---|---|
| iPhone 15 Pro (ProRAW) | 48 MP | 12-bit | DNG (ProRAW) | ~75 MB |
| Sony A6700 (APS-C) | 26 MP | 14-bit | ARW compressed | ~30 MB |
| Nikon Z6 III | 24.5 MP | 14-bit | NEF lossless | ~28 MB |
| Canon EOS R5 | 45 MP | 14-bit | CR3 / C-RAW | ~45 / ~30 MB |
| Sony A7R V | 61 MP | 14-bit | ARW compressed | ~55–65 MB |
| Fujifilm GFX 100 II | 102 MP | 16-bit | RAF lossless | ~200 MB |
| Phase One IQ4 150MP | 150 MP | 16-bit | IIQ lossless | ~300 MB |
| Hasselblad X2D-100C | 100 MP | 16-bit | 3FR lossless | ~210 MB |
What is the difference between lossless and lossy RAW compression?
Lossless RAW compression (Nikon's lossless compressed NEF, Canon's full RAW, Sony's uncompressed ARW) reduces file size by 30–50% using mathematically reversible compression. Every bit of the original sensor data is fully recoverable — identical to uncompressed. Lossy RAW compression (Canon C-RAW, Nikon small RAW, some Sony options) applies irreversible compression, further reducing file size by 40–60% but with a small quality reduction, primarily in highlight and shadow recovery latitude. For most photography, lossy RAW is acceptable; for critical commercial, fine-art, or heavy post-processing work, use lossless or uncompressed.
What is DNG and should I convert my RAW files to DNG?
DNG (Digital Negative) is an open RAW format developed by Adobe as a universal standard, aiming to replace proprietary manufacturer formats. Benefits of DNG: self-contained metadata (no separate .XMP sidecar files needed), future-proof format maintained by an industry standard body, compatible with more software than proprietary formats. Drawbacks: conversion takes time, some manufacturer-specific features may not translate, and DNG compatibility isn't universal. For archival purposes, DNG is a strong choice; for workflow speed, proprietary RAW with XMP sidecars is faster.
Does RAW bit depth affect image quality in visible ways?
In practice, the difference between 12-bit and 14-bit RAW is most visible in shadow recovery and subtle gradient smoothness. 14-bit RAW contains 4× more tonal levels (16,384 vs. 4,096) per channel, providing more headroom for aggressive shadow lifting and color grading without posterization (banding in gradients). For commercial and fine-art work where heavy adjustments are expected, 14-bit is worth the larger file sizes. For high-volume event and sports photography where speed is priority, 12-bit compressed RAW often delivers faster buffer clearance with negligible quality difference at normal processing.
Why do some cameras offer different RAW compression options?
Cameras offer multiple RAW formats to let users balance file size against quality and performance: higher compression = smaller files = more images on a card + faster buffer clearance, but with some quality reduction. Uncompressed = maximum quality but 2× larger files and slower buffer performance. Many photographers use compressed RAW for action, events, and high-volume shooting, switching to lossless for landscape, studio, or fine-art work. Some cameras also offer a 'Small RAW' that reduces the pixel output before writing — this is a true resolution reduction, not just compression.
How much does RAW file size vary between different cameras at the same megapixel count?
Significantly. File size depends on compression algorithm, bit depth, and metadata included: Two 24 MP cameras may produce RAW files ranging from 20 MB (compressed) to 50 MB (uncompressed). Fujifilm's X-Trans sensor produces larger files than equivalent Bayer sensors due to X-Trans pattern complexity. Medium format cameras produce files 3–4× larger than full-frame at similar megapixel counts due to 16-bit capture and less aggressive compression. Always check real-world file sizes from user reports rather than calculated estimates.
Should I use RAW or JPEG for high-volume event photography?
For event photography requiring fast delivery (same-day highlights, news), JPEG is practical — smaller files, faster workflow, immediate sharing. For most professional work, RAW is recommended: provides crucial exposure recovery latitude (1–3 stops), allows white balance correction after the fact (important under mixed or difficult lighting), enables noise reduction on raw sensor data, and provides a permanent master file independent of any particular software version. Many photographers shoot RAW+JPEG: RAW as the archival master for editing, JPEG as the quick-share or proof file.
How do I calculate how many RAW images fit on a memory card?
Images per card = Card capacity (MB) / Average RAW file size (MB). For a 256 GB card (262,144 MB) shooting 50 MB RAW files: 262,144 / 50 = 5,242 images. Note: always use 90% of capacity as the practical limit — never fill cards completely, as performance degrades and data corruption risk increases at near-full capacity. Manufacturers sometimes use '256 GB' to mean 256,000 MB (not 262,144 binary MB), so verify actual card capacity in MB from the manufacturer's specifications.
Pro Tip
Check whether your editing software supports your camera's specific RAW format before a critical shoot. Adobe Camera Raw (Lightroom, Photoshop) updates support for new camera RAW formats approximately 1–3 months after a camera release. If you shoot with a newly released camera, verify compatibility or shoot DNG in-camera as a universal fallback.
Did you know?
The Hubble Space Telescope's Wide Field Camera 3 captures astronomical images at 16-bit depth with a 4096 × 4096 pixel sensor — producing single-frame RAW files of 33 MB. However, images of objects like the Pillars of Creation are composites of hundreds of individual exposures combined and mosaiced, with the final processed image reaching hundreds of megapixels and gigabytes in size.