Storage · Interactive calculator

SD Card & Memory Card Calculator

Calculate photo count and video recording time for SD, microSD, CFexpress, or other memory cards from usable capacity, average file size, bitrate, and buffer.

Interactive calculatorFormula shownVisible assumptions
Updated 2026-06-24
Calculation method MEMORY_CARD-1.0
Page type Interactive calculator
Tool type Formula shown

Estimate photo and video card capacity

Enter card size, buffer percentage, average photo size, and video bitrate to estimate still-photo capacity, video recording time, and when a spare card is safer.

Primary result

Estimated photos 4,608
Estimated video time 2.6 hr
Video minutes 153.6 min
Card size 128 GB
Average photo size 25 MB
Video bitrate 100 Mbps
Usable planning buffer 115.2 GB (10% reserved)

Photo count and video time both use decimal GB with a 10% planning buffer reserved before dividing by average file size or bitrate.

Quick answer

A 128 GB card with a 10% planning buffer and 25 MB photos holds roughly 4,608 photos. At 100 Mbps video, the same usable-capacity assumption gives about 153.6 minutes, or 2.6 hours.

Best for: comparing realistic scenarios before acting. Not for: final professional guidance, emergency decisions, or replacing product labels and local requirements.

How to use the calculator

  1. Enter the labeled card capacity and choose a buffer that leaves room for filesystem overhead and safety margin.
  2. Enter an average photo file size from your camera or a recent shoot.
  3. Enter video bitrate in Mbps from the camera menu or codec documentation.
  4. Use the photo count and video time to decide whether to carry spare cards.

What the results mean

Photo count and video time are planning estimates after a safety buffer. The result is most useful when the file size and bitrate match your actual camera settings.

Decision notes for this calculator

How to interpret this calculator

Card capacity, RAW/JPEG file size, video codec bitrate, usable-space buffer, and spare-card margin drive the estimate.

Sources and assumptions

Use the inputs, units, and assumptions shown on the page, then compare important results with product documentation, vendor guidance, local code, or a qualified professional when the decision has safety or cost consequences.

Method version: MEMORY_CARD-1.0. Send corrections through the contact page.

What to do next

Check the camera bitrate and recording format, format cards in-camera, and carry spare media for shoots you cannot repeat.

Plan SD card capacity for photos and video

Use this memory card calculator when a camera, drone, dashcam, or action camera lists storage in GB but your footage depends on file size or bitrate. The result separates photo count from video recording time because those use different inputs.

  • Inputs: card capacity, average photo size, video bitrate, and planning buffer.
  • Outputs: estimated photo count, video time, video minutes, usable capacity after buffer, and bitrate basis.
  • Best use: compare SD and microSD card sizes before a trip, event, inspection, or field shoot.
  • Limitations: codec, frame rate, resolution, variable bitrate, burst shooting, dual recording, and camera file-splitting can change real capacity.

If your footage must be transferred or retained, also check the download time calculator, surveillance storage calculator, and memory timing calculator for adjacent storage decisions.

Estimate SD card photos and video minutes

This SD card calculator answers two planning questions at once: how many photos fit on the card and how many minutes of video the same card can hold. The video result uses bitrate, not just resolution, because 4K clips can vary widely by codec and camera settings.

  • Inputs: card size, usable-capacity buffer, average photo size, and video bitrate.
  • Outputs: estimated photo count, video minutes, usable capacity after buffer, and a spare-card reminder.
  • Related tools: use the download time calculator for offload time and the surveillance storage calculator for multi-camera retention.

Formula / methodology

Usable GB = capacity GB × (1 − buffer percent). Photos = usable GB × 1,000 ÷ average photo MB. Video seconds = usable GB × 8,000 ÷ bitrate Mbps. The default reserves a 10% planning buffer for both photos and video.

Assumptions and limitations

  • Inputs are assumed to be measured accurately and entered in the units shown.
  • Rounding is intentional so the result is easier to use in real decisions.
  • Vendor-specific behavior, local code, product labels, and regional pricing can override a generic calculator.
  • Health, legal, tax, emergency, structural, chemical, and other high-risk decisions need qualified guidance beyond a web calculator.

Example calculation

Input: 128 GB card, 10% buffer, 25 MB photos, 100 Mbps video. Usable planning capacity is 115.2 GB, so the default is about 4,608 photos or 153.6 minutes (2.6 hours) of video.

The worked example uses the same default scenario so the formula can be followed without running JavaScript.

Common mistakes

  • Using the labeled card size instead of the usable planning capacity.
  • Mixing decimal GB with binary GiB without noting the assumption.
  • Ignoring video bitrate; resolution alone does not determine recording time.
  • Planning an event without spare cards or a safety margin.

FAQ

What formula does this page use?

Photo count = card MB ÷ average file MB. Video time = card bits ÷ bitrate. Use a buffer because cards may not provide their full labeled capacity.

What changes the result the most?

Card capacity, average photo size, video bitrate, and the 10% planning buffer drive how many photos or minutes fit.

How should I use this result?

Use it as a planning estimate and compare important decisions with product documentation, labels, quotes, local code, or qualified guidance.

Why does this page show warnings?

Warnings call out assumptions that can materially change the result or create safety, cost, or reliability problems.

Can I share this scenario?

Yes. The share button copies a URL with the current inputs, while the main page remains the base calculator URL.

Method details

Updated: June 24, 2026. Calculation method: MEMORY_CARD-1.0. Availability: interactive calculator.