How long will 1 TB record security cameras?
By Devin Chua · Data checked by Owen Nakamura · Updated At 1080p with H.265, 1 TB records one camera for about 32 days — or four cameras for roughly 8 days — recording 24/7. At 4K it is far less: about 8 days for one camera. Codec and motion-only recording change it dramatically; the table and calculator below give your exact figure.
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Days 1 TB records, by resolution and codec (24/7)
| Resolution | Codec | 1 camera | 4 cameras |
|---|---|---|---|
| 1080p (2MP) | H.265 / HEVC | 32 days | 7.9 days |
| 1080p (2MP) | H.264 | 16 days | 4.0 days |
| 2K / 4MP | H.265 / HEVC | 18 days | 4.4 days |
| 2K / 4MP | H.264 | 9 days | 2.2 days |
| 4K / 8MP | H.265 / HEVC | 8 days | 2.0 days |
| 4K / 8MP | H.264 | 4 days | 1.0 days |
Per 1 TB of usable space, recording 24/7 with ~20% overhead. Motion-only recording extends these in proportion to how quiet the scene is.
Size it exactly
Pre-filled for this question — change any input to model your own setup.
3.2 TB of footage over 30 days, +20% overhead = 3.8 TB
The days-per-TB numbers
1 TB is 1,000 GB of usable space. A camera's daily appetite is its bitrate turned into bytes: at 1080p H.265 (~2.5 Mbps) that is about 26 GB a day, so 1 TB lasts roughly a month for one camera — but only about a week once you run four. Bump to 4K and the same terabyte is gone in about eight days per camera.
The single biggest variable is the codec: H.265 (HEVC) roughly halves the storage of the older H.264 for the same picture, so an H.264 camera empties 1 TB in about half the time. After that it is resolution, then frame rate, then how much of the day you actually record.
Motion-only stretches it — honestly
If you record motion only, 1 TB lasts longer in proportion to how quiet the scene is: a still hallway that triggers 20% of the day makes 1 TB last five times longer, while a busy street that records most of the day barely helps. Treat motion savings as scene-dependent, not a fixed multiplier — the calculator lets you set the duty cycle and shows the effect.
For most people 1 TB is simply too small for a modern multi-camera 4K setup; the calculator will size the real array (and the surveillance drives) you need for your retention target.
Frequently asked questions
How long will 1 TB last for 4 security cameras?
About 8 days for four 1080p H.265 cameras recording 24/7, or roughly 2 days for four 4K cameras. H.264 halves those figures; motion-only recording extends them by however quiet your scenes are. Use the calculator for your exact bitrate and hours.
How many days of footage is 1 TB?
For one 1080p H.265 camera, about 32 days at 24/7; for one 4K camera, about 8 days. It scales inversely with camera count and bitrate — four cameras get a quarter of the days, and H.264 halves them again.
Is 1 TB enough for a security camera system?
For a single 1080p camera with modest retention, yes; for a multi-camera or 4K system, rarely. Most NVR setups need several terabytes — the calculator sizes the array and recommends surveillance drives for your camera count and retention.
Does H.265 really double how long 1 TB lasts?
Roughly, yes. H.265/HEVC encodes the same image at about half the bitrate of H.264, so a terabyte of storage lasts about twice as long. If your cameras support H.265, enabling it is the cheapest way to extend retention.
Read more
Devin Chua works out which drives, RAM and NVMe cache fit which NAS model at nasdrives.ca, and what the RAID choice means for usable capacity, checked against what is in stock on Amazon.ca.
Data checked by Owen Nakamura, Technical editor (data checking)