Oct 25, 2026 | 1 min read

How Much Storage Do Security Cameras Need? A Simple Way to Estimate

Estimate how many days of footage your recorder will hold, with a worked example and Lorex storage options.

Lorex surveillance-grade hard drive for DVR and NVR security systems

How long will your recorder keep footage before it runs out of space? The answer depends on how many cameras you have, how sharp they are and how they record. This guide gives you a simple way to estimate storage, with a worked example you can adapt.

The short answer

Storage needed = how much video each camera records per day × number of cameras × days you want to keep. More cameras, higher resolution and nonstop recording all use more space. Recording on motion stretches it.

Three things that decide storage

  • Cameras and resolution. Sharper video (see our resolution guide) generally means larger files. Every extra camera adds to the total.
  • Recording mode. Continuous recording writes all day. Motion-based recording only writes when something happens, so the same drive lasts longer on a quiet property.
  • Days you want to keep. Recorders typically record over the oldest footage once the drive is full, so the drive size sets how far back you can look.

A worked example

The figures below are an illustration, not a Lorex specification. Real video bit rates depend on the camera, the scene and your settings, so check your recorder for actual numbers.

Assume each camera records at 4 megabits per second, nonstop. That is 0.5 megabytes per second, or about 43 GB per camera per day (0.5 MB × 86,400 seconds). With 8 cameras, that is roughly 345 GB per day.

Hard drive size Days of nonstop recording (8 cameras at 4 Mbps)
2TB About 5 to 6 days
4TB About 11 to 12 days
6TB About 17 days
8TB About 23 days
10TB About 29 days

Usable space is slightly less than the number on the drive label, and motion recording can multiply these figures on a quiet property. Use the table as a starting point, then adjust.

Wi-Fi cameras use microSD cards

A stand-alone Wi-Fi camera saves to a microSD card. At the same example rate, a 32GB card would fill in under a day of nonstop recording, which is why these cameras often record motion events rather than nonstop. Some models include a 32GB card and accept up to 256GB, and Lorex sells surveillance-grade cards built for always-on recording.

Storage options at The Galaxy Store

Lorex Connect VC 4K 8-Channel NVR, 1TB
Lorex Connect VC 4K 8-Channel NVR, 1TB

Includes 1TB of storage with 8 built-in PoE ports, and expandable local storage up to 10TB.

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Lorex 4K 16-Camera-Capable 4TB NVR System with Nocturnal 3 Bullet Cameras
Lorex 4K 16-Camera-Capable 4TB NVR System with Nocturnal 3 Bullet Cameras

A 4TB recorder with 12 or 16 Nocturnal 3 cameras. Supports up to 16 cameras, so you can add more later.

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Surveillance-Grade Hard Drive (4TB, 8TB or 10TB)
Surveillance-Grade Hard Drive (4TB, 8TB or 10TB)

For adding or upgrading storage in a DVR or NVR. Lorex describes it as a WD Purple drive designed for security recorders.

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256GB microSD Card (Surveillance Grade)
256GB microSD Card (Surveillance Grade)

Built for always-on recording in Wi-Fi cameras and other devices with a microSD slot.

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Lorex 4K Dual Lens Wi-Fi Security Camera with Smart Security Lighting
Lorex 4K Dual Lens Wi-Fi Security Camera with Smart Security Lighting

Includes a pre-installed 32GB microSD card, upgradable to 256GB.

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Frequently asked questions

Can I add a bigger hard drive later?

Many recorders allow it. Check the maximum drive size in the recorder’s specifications. For example, the Connect VC 8-channel NVR lists expandable storage up to 10TB.

Does 4K need more storage than 1080p?

Generally yes, because higher resolution produces larger files. Settings and the scene also matter, so the best check is your own recorder’s storage readout.

How do I make the drive last longer?

Record on motion instead of nonstop, add a larger drive, or lower the resolution or frame rate on cameras that cover low-priority areas.

Do I need a special hard drive?

Use a surveillance-grade drive, which is designed for recording around the clock. Lorex lists its drive as a WD Purple model for DVR and NVR systems.

Choose the right storage

Recorders, hard drives and microSD cards.

Recorders ➜Hard drives and microSD ➜Complete systems ➜

Keep reading

The Galaxy Store is an authorized Lorex partner. Free standard shipping on orders of $150 or more to Canada and the US. Questions about which model fits? Use our Contact page.