Arri Alexa Data Calculator

Estimate recording data, storage needs, card runtime, and offload planning for common ALEXA shooting scenarios. Select your codec, resolution tier, frame rate, duration, and media size to generate a practical field estimate for production and DIT workflows.

• Built for fast onset storage planning
• Useful for DITs, camera assistants, producers, and post teams
• Includes card runtime and archive sizing estimates

Expert Guide to Using an ARRI Alexa Data Calculator

An ARRI Alexa data calculator helps production teams estimate how much storage they will need before the camera package ever reaches set. That sounds simple, but in professional cinema workflows, small errors in bitrate assumptions can trigger expensive operational problems. If your estimate is too low, the camera team runs out of media, the DIT falls behind on cloning, and editorial receives footage later than planned. If your estimate is too high, production overspends on cards, shuttle drives, and archive media. The goal of a good calculator is not only to output gigabytes, but to support practical decisions about card counts, data wrangling speed, backup strategy, and overall schedule risk.

The ALEXA platform has earned its reputation because of color science, highlight handling, and dependable image quality across a broad range of codecs and recording modes. But those strengths also mean footage sizes can vary dramatically. A compressed ProRes recording at a modest resolution and frame rate behaves very differently from ARRIRAW at higher frame rates or larger sensor modes. When people search for an “arri alexa data calculator,” they usually want a fast answer to one question: how much storage will I need? In reality, the better question is: how much recording media, clone capacity, verification time, and archive space will I need for this exact shooting plan?

What the calculator actually estimates

This calculator uses a field-planning approach. It starts with an estimated baseline data rate for a selected codec, then scales that estimate by resolution tier, frame rate, camera profile, and optional safety overhead. The result is a practical planning number, not a replacement for official engineering specifications for every exact mode. That distinction matters because real-world file sizes can change based on recording format, sensor mode, frame rate, firmware generation, and whether the codec uses variable or constrained data behavior. For preproduction and onset planning, however, a robust estimate is exactly what most teams need.

• Codec: ARRIRAW generally creates the largest files, while ProRes 422 LT creates substantially smaller ones.
• Resolution tier: More pixels generally means larger files and faster media turnover.
• Frame rate: Increasing frames per second usually raises total recorded data per minute.
• Camera profile: Different ALEXA generations and sensor families can shift the practical planning envelope.
• Backup overhead: Real productions need room for folder structure, checksum workflows, duplicate copies, and safety margin.

Important planning note: A storage estimate should include more than camera originals. Professional jobs often require at least two verified copies in the field, plus a shuttle or nearline copy for post. If the camera originals are 2 TB, the practical media plan may be 4 TB to 6 TB or more depending on redundancy and retention.

Why ARRI Alexa storage planning matters so much

The ALEXA family is regularly used on commercials, scripted features, documentary production, branded content, and high-end streaming work. On those productions, media management is connected to every downstream department. Camera reports, LUT handling, dailies generation, backup verification, and turnover schedules all depend on accurate data expectations. A one-day commercial shoot may be able to absorb some estimation error. A ten-day episodic block or a feature with high shooting ratios usually cannot.

Storage planning affects:

1. How many cards are needed on set. If a card fills in 20 minutes instead of 35, the camera team needs a different rotation plan.
2. How quickly the DIT must offload. A higher bitrate codec can create sustained copy workloads that require faster readers and SSDs.
3. How much backup hardware must travel. Underestimating protected storage causes same-day bottlenecks.
4. How long clone and verification takes. Bigger files do not just require bigger drives. They require more time to checksum and verify.
5. Post production ingest planning. Editorial, VFX, and archive teams all benefit from accurate volumes early.

Typical planning statistics for ARRI Alexa workflows

The table below shows commonly used planning figures for storage estimation. These are practical baseline estimates used for budgeting and workflow planning, not a substitute for mode-specific manufacturer documentation. The baseline values below assume a 24 fps, standard planning profile before the calculator applies resolution and profile multipliers.

Codec	Estimated Baseline Data Rate	Approximate Data per Hour	Typical Use Case
ARRIRAW estimated	330 MB/s	1.16 TB/hour	Maximum image flexibility, premium VFX and grading workflows
ProRes 4444 XQ estimated	110 MB/s	396 GB/hour	High-end finishing with strong latitude and efficient post handling
ProRes 4444 estimated	82 MB/s	295 GB/hour	Premium mastering and robust image quality with smaller files
ProRes 422 HQ estimated	59 MB/s	212 GB/hour	Broadcast, documentary, corporate, and general premium acquisition
ProRes 422 estimated	39 MB/s	140 GB/hour	Balanced quality and storage efficiency
ProRes 422 LT estimated	26 MB/s	94 GB/hour	Long-form recording where efficiency is a primary concern

Those differences are substantial. ARRIRAW at the planning baseline is roughly 12.7 times heavier than ProRes 422 LT and about 5.6 times heavier than ProRes 422. That ratio matters when you convert a shooting ratio into media demand. For example, a production expecting six hours of total recorded material could end up around 6.96 TB at the ARRIRAW baseline, but only around 564 GB in ProRes 422 LT before safety overhead. Once you create duplicate verified copies, the gap becomes even more operationally significant.

How to think about card runtime

Another reason to use an ARRI Alexa data calculator is card turnaround. A card is not only a storage container. It is a scheduling unit. If your codec and frame rate reduce a 512 GB card to a short runtime window, the 2nd AC and DIT need a reliable swap rhythm. Productions often focus on total terabytes and forget that media rotation can become the first point of failure. It only takes one delayed card return to slow down principal photography.

Media Size	ARRIRAW Baseline Runtime	ProRes 4444 XQ Baseline Runtime	ProRes 422 HQ Baseline Runtime
256 GB	About 13.2 minutes	About 39.8 minutes	About 74.1 minutes
512 GB	About 26.4 minutes	About 77.6 minutes	About 148.2 minutes
1 TB	About 51.7 minutes	About 155.2 minutes	About 296.4 minutes

These baseline runtimes are highly useful in prep meetings because they turn abstract bitrate discussions into operational decisions. A camera operator, 1st AC, line producer, and DIT can all immediately understand what a 13-minute card means on a high-pressure day with long takes or heavy reset time.

Best practices for estimating a real production day

To use the calculator effectively, begin with the actual creative plan, not an optimistic average. If the job includes high speed capture, larger sensor modes, or a VFX-heavy deliverable, calculate those sequences separately. The biggest mistake in camera data planning is blending everything into one average number that looks convenient but hides the worst-case moments. A better workflow is to estimate in layers:

1. Calculate the base storage for your normal dialogue or coverage setup.
2. Add separate estimates for any high frame rate sequences.
3. Add another estimate for specialty formats or open-gate capture.
4. Apply a realistic shooting ratio based on the director and schedule.
5. Add backup overhead for verified duplicate copies and short-term post handoff.

For example, if a commercial plans 90 minutes of total recorded material in ProRes 4444 XQ for the main unit, then another 20 minutes of high-speed material, the proper approach is not to estimate the entire day at one average number. Calculate each block separately, then sum the results. That method gives more accurate card rotation timing and a more truthful sense of how much nearline storage the DIT cart needs.

Data rate math in simple terms

The core formula is straightforward: data rate multiplied by time equals total data. The complexity comes from choosing a realistic data rate. In this calculator, the selected codec acts as the baseline MB/s value. Resolution, frame rate, and camera profile adjust that baseline. The calculator then converts that figure into gigabytes and terabytes for planning. Finally, backup overhead expands the number to a safer working capacity. This is especially useful when buying or renting media because it helps distinguish between raw recording need and practical total storage need.

If your estimated data rate is 110 MB/s and you record for 60 minutes, the rough total is:

• 110 MB every second
• 6,600 MB every minute
• 396,000 MB every hour
• About 396 GB per hour using decimal planning units

With a 20% overhead, that 396 GB becomes approximately 475.2 GB of protected planning capacity. If production requires two verified copies plus one shuttle copy, practical field storage can climb much higher than the original recorded size. That is why professional data planning should always account for workflow, not just capture.

ARRIRAW versus ProRes in practical storage terms

Choosing between ARRIRAW and ProRes is not only a creative or postproduction decision. It is a logistics decision. ARRIRAW offers extensive flexibility for finishing, but it raises pressure on media capacity, transfer time, and backup architecture. ProRes, especially in 422 families, dramatically reduces the burden on cards and drives while still delivering excellent image quality for many projects. The right choice depends on delivery requirements, color pipeline, VFX involvement, schedule, and budget.

Ask these questions during prep:

• Will the project benefit enough from ARRIRAW to justify larger media and longer clone times?
• Does post prefer ProRes for faster ingest and lower storage cost?
• Are there sequences that should be captured differently from the rest of the production?
• Can the DIT workstation sustain the expected throughput with verification enabled?

Why backup overhead should never be ignored

Many crews underestimate overhead because they focus on the original camera negative volume. In practice, protected storage planning should include room for checksum reports, file system behavior, naming structures, and duplicate media sets. A 10% to 30% overhead is a sensible planning range for many jobs. Larger jobs with multiple handoff targets may need more. The most expensive drive is the one you forgot to bring.

For broader guidance on digital preservation, media management, and storage planning, review authoritative resources such as the Library of Congress digital formats guidance, the National Institute of Standards and Technology, and the U.S. National Archives records management resources. While these sources are not camera-specific workflow manuals, they are highly relevant to the broader principles of file integrity, storage lifecycle, and long-term media stewardship.

Practical recommendations for producers, DITs, and camera teams

If you are producing a shoot, use the calculator early and communicate the result in plain language: expected data per hour, expected daily total, recommended card count, and protected backup target. If you are the DIT or data wrangler, use the estimate to size your clone stations, SSD staging volume, and end-of-day archive plan. If you are in the camera department, pay close attention to card runtime rather than only total day size. Runtime dictates whether your media rotation feels calm or chaotic.

Field rule: If the calculated total is close to your available capacity, you do not have enough capacity. Build margin for reshoots, unexpected high-speed takes, and one more backup than you think you need.

Final takeaway

An effective ARRI Alexa data calculator is really a production planning tool. It translates codec and frame-rate choices into card changes, copy time, drive cost, and schedule pressure. Use it before prep, again when the camera mode is locked, and one more time before principal photography begins. That habit helps eliminate one of the most preventable failures in digital cinematography: discovering too late that the storage plan was based on guesswork instead of math.

Use the calculator above to estimate your next shoot, then add practical buffer for backups, turnover, and archive retention. When storage planning is done correctly, the camera team shoots confidently, the DIT keeps up, and post receives media on time with a cleaner, safer handoff.