iPhone and mobile creator storage
iPhone ProRes Recording Time Calculator
Estimate recording duration from SSD capacity, reserved free space and the expected codec data rate. The result is a planning figure that should be replaced with a test measurement before a critical production.
Estimate recording time from SSD capacity
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What the recording-time result represents
The calculator converts usable gigabytes into megabytes and divides by the entered data rate. It reserves a percentage of the SSD rather than assuming every advertised gigabyte is available for footage. The result is an approximate continuous duration, not a promise from Apple or the drive manufacturer.
Actual recording time changes with the codec and camera application. A different frame rate or RAW option can change file size. The most accurate input comes from a test recording: divide the file size in megabytes by the clip duration in seconds to estimate the observed data rate.
Why advertised SSD capacity is not fully usable
Manufacturers advertise decimal gigabytes, while operating systems may display a smaller binary figure. Formatting also uses a small amount of space, and a capture drive should not be operated at the last available megabyte. The reserve setting accounts for planning headroom rather than attempting to model every file-system detail.
Keep more reserve when a shoot cannot stop for an offload. Keep less only when the recording schedule is controlled and the drive is monitored closely. The phone and application can also need internal free space even though the video is directed externally.
Using time estimates on set
Create a capacity plan for the full day, not only the longest take. Include rehearsals, false starts, extra angles and safety takes. Compare the expected total with the offload window and the time required to verify copied footage. A drive that records for many hours is not useful if the backup process cannot keep up.
Track remaining space before each important take. Do not depend on a calculation made with a different codec setting. When the application shows less remaining time than expected, treat the application as the current source of truth and investigate the changed data rate or reserved space.
Translate capacity into usable minutes cautiously
The calculator divides estimated usable storage by the selected data rate to produce approximate recording time. That result is not a guaranteed maximum. Codec behavior, audio, metadata, application overhead and scene complexity can alter file size. The purpose is to compare capacities and plan shooting blocks, not to promise that a 1TB drive will stop at one exact minute on every phone and application.
Choose the closest workflow profile or enter a measured custom rate. When a production alternates between modes, calculate each segment separately or use the highest rate for a conservative result. A creator expecting twenty minutes of 4K120 and two hours of 4K60 will get a better estimate by modeling both than by averaging them casually.
Reserve space for formatting overhead and uncertainty
Manufacturers advertise decimal gigabytes, while operating systems may display capacity differently and the formatted volume consumes some space. Existing files, hidden metadata and application behavior reduce what remains available for new footage. The calculator applies a usable-space assumption so the displayed minutes are not based on every advertised byte. Keeping an additional margin protects against a session running longer than planned.
Do not continue recording until a drive is completely full. Low free space can complicate file management and leaves no room for an extra take. Set a practical stop point and prepare another tested SSD before reaching it. For events, switching drives during a scheduled break is safer than waiting for an emergency warning in the middle of a continuous segment.
Use the estimate to plan media rotation
Recording time becomes useful when tied to a rotation plan. Decide which drive is active, which is being copied and which is ready as a spare. Label volumes and physical devices so footage cannot be erased by mistake. Note the start and end time of each card or SSD roll, especially when multiple phones are involved. This operational discipline matters more than squeezing the last few minutes from a larger drive.
Estimate offload duration as well as capture duration. A full multi-terabyte SSD can take a long time to duplicate through a slower laptop port or destination HDD. If the copy time exceeds the available break, use a second capture drive or a faster verified offload system. Cloudzat’s transfer-time calculator can expose the slowest link before the schedule is finalized.
Confirm the mode is supported by the phone and drive
A time estimate does not establish compatibility. External 4K60 ProRes requires at least 220 MB/s write performance, while 4K120 requires 440 MB/s. The latter mode also depends on a later Pro iPhone that exposes external 4K120 capture. ProRes RAW has an additional host requirement. Select the real phone profile so the engine can reject an impossible combination instead of calculating minutes for a mode the handset cannot record.
The storage must be prepared as exFAT, remain unencrypted for the recording session and connect through a USB 3 cable rated at least 10 Gbit/s. Directly attached storage must stay within the 4.5 W power limit. A drive with enough capacity but an unknown power requirement should be tested or verified before it is used for a long production.
Calibrate the calculator with a real sample
Record ten or fifteen minutes using the exact app, codec and scene style, then divide the resulting file size by the duration. Enter that measured rate as a custom value when it differs from the generic profile. Motion, detail and application implementation can influence the result, so a real sample from the intended workflow is the best calibration source.
Repeat the sample after major changes such as a new camera app, codec setting or phone update. Keep the measured value with the project notes and use it to decide when drives should be switched. The calculator is most dependable when it combines published requirements with evidence from the creator’s own equipment.
Frequently asked questions
How many minutes fit on a 1TB SSD?
It depends on the actual data rate. Enter the measured mode-specific rate for a meaningful estimate.
Why does the tool reserve space?
The drive should not be planned to 100 percent full, and advertised capacity is not identical to displayed usable space.
Does frame rate change recording time?
Yes. Higher frame rates usually increase the data rate and reduce duration.
Can I use the Apple minimum write speed as the codec data rate?
No. The minimum write speed is a device-performance threshold. The actual file data rate can be different.
Should I erase clips on the capture SSD during a shoot?
Only after footage has been copied and verified. Deleting individual clips can complicate media management.
Can the estimate replace a test recording?
No. Use a long test in the exact mode to verify capacity, speed, heat and stability.