Camera Memory Card Capacity Calculator

Shoot preset:

Choose a common camera job, then adjust the values to match your shoot.

Card size:

Enter the labeled size for one card, such as 64, 128, 256, or 512 GB.

GB/card

Cards packed:

Total physical cards available for the shoot; dual backup mode pairs cards by slot.

cards

Recording mode:

Choose how the camera uses cards: one slot, overflow pool, or mirrored backup slots.

Still photos:

Use expected shutter count, delivered coverage count, or a conservative event estimate.

photos

Photo size source:

Measured file size is best when you have sample files from the same camera settings.

Camera resolution:

Enter the sensor output megapixels after crop mode, for example 24, 33, 45, or 61 MP.

Photo format:

Use the setting you expect to shoot most of the event with.

Average photo file:

Use the average size of real images from the camera settings you will use.

MB/photo

Video runtime:

Enter recorded minutes, not event duration; set to 0 for stills-only planning.

min

Video recording profile:

Use the camera menu bitrate when available; presets are conservative planning shortcuts.

Video bitrate:

Common mirrorless values range from 50 Mb/s H.264 to 735+ Mb/s ProRes.

Mb/s

Selected card speed:

Use the printed V-rating, U-rating, or verified sustained write speed class.

Spare card reserve: {{ reserve_pct }}%

A 10-20% reserve keeps the last card from running completely full.

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Card capacity basis:

Decimal GB follows card labels; binary GiB follows 1024-based computer readouts.

Burst rate:

Enter frames per second for the fastest sustained burst you expect to use.

fps

Longest burst:

Set to 0 if burst shooting is not relevant to this shoot.

Burst recovery target:

Shorter recovery targets require faster cards; 30 seconds is a conservative field baseline.

Camera memory card capacity plan
Metric	Value	Planning use	Copy
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Camera shoot storage mix
Component	Storage	Share	Assumption	Copy
{{ row.component }}	{{ row.storage }}	{{ row.share }}	{{ row.note }}

Alternative camera memory card scenarios
Card size	Physical cards	Usable per card	Fit signal	Copy
{{ row.cardSize }}	{{ row.cards }}	{{ row.usable }}	{{ row.signal }}

Camera memory card speed check
Check	Value	Next action	Copy
{{ row.check }}	{{ row.value }}	{{ row.action }}

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A camera memory card plan has to answer more than "how many gigabytes are on the label?" A card kit can have enough space for stills and still fail a high-bitrate video mode. It can fit the planned shoot and still leave too little reserve for extra takes, delayed backups, or a card that needs to stay untouched until delivery is confirmed. Capacity, recording mode, and sustained write speed all matter before a shoot starts.

Still photos and video stress cards in different ways. Stills arrive as many separate files, and each file changes with megapixels, compression, RAW settings, JPEG quality, and subject detail. Video is closer to a continuous stream, so bitrate and recorded minutes dominate. Burst shooting adds another speed question because the card may need to drain a large buffer quickly enough for the next action sequence.

Capacity: The usable space from card size and card count after choosing a decimal GB or binary GiB planning basis.
Reserve: Extra space for overruns, retakes, filesystem overhead, delayed offload, and safety margin.
Overflow pool: A dual-slot mode that treats cards as extra space rather than duplicate backup copies.
Dual backup: A mirrored recording mode where each slot needs a full copy of the shoot, so physical card demand doubles.
Sustained write: The continuous MB/s a card must maintain for recording or buffer clearing, which is different from a peak read speed printed on packaging.

Memory card diagram divided into stills, video, reserve, and spare space with a sustained write-speed arrow.

Card planning is strongest when it starts from real camera settings. A label such as 4K, 8K, RAW, or JPEG fine is not enough because bitrate and compression can vary widely between camera bodies and menu choices. A short test shoot gives better average photo sizes than a generic per-megapixel estimate, and the camera maker's media list can be stricter than a generic speed-class rule.

No calculator can replace media handling discipline. Critical work still needs card rotation, clear labels, backup habits, and enough physical cards to handle schedule changes. The number is a pre-shoot planning check, not a guarantee that a specific card brand, firmware version, reader, or camera body will sustain every advertised mode under heat, low battery, or buffer pressure.

How to Use This Tool:

Start from a realistic shoot preset, then replace the values that are known for the actual camera and job.

Choose Shoot preset or Custom. Presets fill a starting card size, card count, recording mode, still volume, video bitrate, reserve, and speed class.
Enter Card size, Cards packed, and Recording mode. The summary shows whether packed cards cover the required storage or how many more cards are needed.
Enter Still photos and choose Photo size source. Use estimated format math for early planning or Measured average file size when sample files are available.
Enter Video runtime and Video bitrate. Use the camera-menu bitrate when possible, or choose a video recording profile to fill a common value.
Set Selected card speed and Spare card reserve. The Speed Check result compares the selected class with the modeled sustained write demand.
Open Advanced when decimal GB versus binary GiB, burst rate, longest burst, or burst recovery time changes the plan.
Review Capacity Plan, Shoot Mix, Card Scenarios, and Speed Check. If a validation warning appears, correct card size, reserve percentage, or burst recovery time before trusting the result.

Interpreting Results:

Required with reserve is the planned shoot size after the reserve percentage is added. Cards required rounds that storage up to whole physical cards, and Packed-card margin tells whether the cards in the bag cover the plan. A negative margin is a clear shortage. A small positive margin can still be risky when offload timing is uncertain.

Speed Check is separate from capacity. A card kit can have enough gigabytes and still be too slow for the selected video bitrate or burst recovery target. When Selected card class does not clear the modeled demand, choose a faster class, reduce the bitrate, slow the burst workflow, or confirm the camera maker's approved media list.

Dual-slot backup deserves special attention. The creative workload does not double, but physical cards do because each slot needs a full copy. Overflow recording treats cards as a larger pool, which can reduce card count but does not provide mirrored capture protection.

Technical Details:

The capacity model combines still-photo storage, video storage, reserve, and card rounding. Photo size can come from a measured average or from megapixels multiplied by a format estimate. Video storage comes from bitrate converted from megabits per second to megabytes per second, then multiplied by recorded minutes. Reserve is added before card count rounding so the plan does not use every byte of the last card.

The write-speed model takes the larger of two pressures: continuous video recording with 20% headroom, and burst payload draining over the chosen recovery time. Speed-class labels are interpreted as minimum sustained write values, not peak transfer claims. That is why a high-capacity card can still fail the modeled speed check.

Formula Core:

\begin{array}{lcl} photo MB & = & measured photo MB or megapixels \times MB per MP \\ video MB & = & \frac{bitrate Mb/s}{8} \times 60 \times video minutes \\ required MB & = & (still count \times photo MB + video MB) \times (1 + reserve rate) \\ cards per slot & = & ceil (\frac{required MB}{usable MB per card}) \\ required write MB/s & = & max (\frac{bitrate Mb/s}{8} \times 1.2, \frac{fps \times burst seconds \times photo MB}{clear seconds}) \end{array}

Camera memory card photo size and capacity rules
Setting	Rule used	Planning meaning
Measured average	Uses entered MB per photo directly	Best when sample files match the camera, format, and compression settings.
JPEG fine	0.45 MB per megapixel	Early estimate for JPEG-heavy travel, events, or coverage work.
Compressed RAW	1.15 MB per megapixel	General RAW estimate when measured files are not available.
Lossless RAW	1.45 MB per megapixel	Higher-file-size RAW planning.
RAW plus JPEG fine	1.60 MB per megapixel	Dual-file still workflows and heavier burst payloads.
Decimal GB	Card size x 1000 MB	Matches the common memory-card label convention.
Binary GiB equivalent	Card size x 1024 MB	Useful when comparing against software readouts that use 1024-based units.

Recording mode and speed-class rules
Mode or class	Boundary used	Important consequence
Single slot	Physical cards = cards per slot	Card count follows required storage divided by usable capacity per card.
Overflow pool	Physical cards = cards per slot	Cards extend recording space without a mirrored duplicate.
Dual-slot backup	Physical cards = cards per slot x 2	Packed odd cards are rounded down to complete pairs for usable backup capacity.
V10, V30, V60, V90	10, 30, 60, and 90 MB/s minimum sustained classes	The smallest class that meets or exceeds required write MB/s is recommended.
CFexpress planning tiers	400 MB/s and 800 MB/s thresholds	Used for high-speed planning when SD video speed classes are not enough.

In the hybrid wedding preset, 2400 RAW plus JPEG photos from a 33 MP camera estimate to 52.8 MB each. Ninety minutes at 150 Mb/s adds 101.3 GB of video, and 20% reserve raises the required storage to about 273.6 GB. With 128 GB decimal cards in dual-backup mode, that rounds to three cards per slot, or six physical cards. The burst setting is more demanding than the video stream in this preset: 8 fps for 5 seconds at 52.8 MB per photo, cleared over 30 seconds, requires about 70.4 MB/s, so the modeled recommendation rises above V60.

Accuracy Notes:

The calculation works from entered planning values. It does not inspect the actual card, camera, file system, firmware, or video codec, and it does not test a card's real sustained write performance.

Measured average photo size is usually better than megapixel estimates once the camera and compression settings are known.
Camera manufacturers may require specific media lists, VPG profiles, or card types for a codec even when the generic MB/s math appears adequate.
Thermal limits, battery level, fragmented cards, counterfeit media, and old firmware can change recording reliability.
Reserve is a planning margin, not a replacement for prompt backups and clear card rotation.

Advanced Tips:

Use Measured average file size after a short test shoot with the same body, crop mode, RAW compression, JPEG quality, and subject type.
Enter the exact camera-menu Video bitrate when available. Resolution alone does not determine storage or write-speed demand.
Raise Spare card reserve for weddings, documentary work, travel, wildlife, or any job where offloading during the shoot is uncertain.
In Dual slot backup mirror, pack cards in even pairs. One unpaired extra card does not increase mirrored capacity.
Shorter Burst recovery target values make the required write speed climb quickly because the same burst payload must drain in less time.
When Selected card class barely clears the modeled target, step up one class or check the camera maker's approved media list.

Worked Examples:

Hybrid wedding day

The hybrid wedding preset starts with 2400 RAW plus JPEG photos, 90 recorded video minutes at 150 Mb/s, 128 GB cards, six cards packed, 20% reserve, and dual-backup recording. The plan needs about 273.6 GB per slot and rounds to six physical cards, so capacity fits, but the default burst settings push the recommended speed above V60.

Travel JPEG coverage

A travel JPEG plan with 1800 photos from a 24 MP camera, 30 minutes of 50 Mb/s video, two 64 GB cards, and 15% reserve needs about 35.3 GB. Single-slot recording fits easily in the packed cards, and the modeled sustained write target is about 7.5 MB/s, so a V30 card has headroom.

Sports burst warning

A sports RAW burst setup with 45 MP compressed RAW, 20 fps for 8 seconds, and a 25-second recovery target creates a burst-drain demand near 331 MB/s. Even if the card capacity is enough, the speed result points to CFexpress-class or manufacturer-approved high-speed media rather than V90 SD cards.

FAQ:

Why does the calculator offer decimal and binary capacity?

Memory cards are commonly sold in decimal gigabytes, while computers and some camera menus may show 1024-based units. Switching the basis helps reconcile those views during planning.

Does a faster card increase capacity?

No. Speed class affects whether the card can sustain recording and burst clearing. Capacity still comes from card size, card count, recording mode, still size, video runtime, bitrate, and reserve.

Why can dual backup need twice as many cards?

Dual backup writes a complete copy to each slot. The shoot size does not change, but each slot needs enough cards to hold the full plan.

Why does the speed warning appear when capacity fits?

Capacity and write speed are separate checks. The warning appears when the selected speed class is below the larger of the video write demand and burst recovery demand.

Should the result replace the camera maker's approved media list?

No. Treat the result as a numeric planning check. Camera makers can require stricter cards for specific codecs, frame rates, firmware versions, or VPG profiles.

Glossary:

Bitrate: The video data rate in megabits per second, converted to megabytes per second for storage and write-speed math.
Reserve: Extra planned capacity added before card count rounding.
Overflow pool: A recording mode where cards extend available space instead of making duplicate copies.
Dual backup: A mirrored recording mode where each slot stores a complete copy of the shoot.
Sustained write: The continuous write speed a card must maintain without dropping recording data.
VPG: Video Performance Guarantee, a CompactFlash Association certification for minimum sustained write performance on CFexpress media.

References:

Speed Class Standards for Video Recording, SD Association.
Capacity (SD/SDHC/SDXC/SDUC), SD Association.
Video Performance Guarantee (VPG), CompactFlash Association.