CCTV IP Camera Storage Capacity & Bandwidth Days Calculator
Sizing an NVR or DVR hard drive correctly means balancing camera resolution, compression codec, frame rate, recording schedule and how many days of footage you legally or practically need to retain. This calculator runs those numbers together so you can buy the right drive the first time instead of running out of storage mid-month.
8 4K cameras recording 24/7 with H265 need about 14.83TB for 30 days — a 16TB HDD covers it.
| Metric | Value |
|---|---|
| Cameras | 8 |
| Resolution | 4K |
| Codec | H265 |
| Frame rate | 15 fps |
| Bitrate per camera | 6.00 Mbps |
| Recording hours/day | 24h |
| Daily GB per camera | 63.28 GB |
| Daily GB (all cameras) | 506.3 GB |
| Total for 30 days | 14.83 TB |
Formula & step-by-step maths
- Base_Bitrate
- Baseline Mbps for resolution tier at 15fps
- Compression_Factor
- Relative bitrate multiplier for codec (H.264=1.0, H.265=0.5, H.265+=0.35)
- hours
- Recording hours per day (24 for continuous, 8 for motion-triggered)
Why codec choice changes storage by half or more
H.264 has been the baseline video codec for over a decade, but H.265 (HEVC) compresses the same visual quality into roughly half the bitrate, and smart codecs like H.265+ add scene-change detection to cut it further during static periods. Upgrading from H.264 to H.265+ on an 8-camera system can turn a 4TB requirement into under 1.5TB for the same retention window.
Continuous vs motion-triggered recording
Recording 24/7 gives complete footage but at roughly three times the storage cost of motion-triggered recording, which typically captures 6-10 active hours per day in a residential or small business setting. High-traffic commercial sites usually need continuous recording for liability reasons, while quieter properties can save significant storage with motion detection alone.
How resolution scales storage demand
Moving from 1080p to 4K roughly triples the raw bitrate need before compression, since 4K carries four times the pixel count of 1080p. For most security use cases, 2K offers a solid middle ground — enough detail for facial recognition and license plates at reasonable distances without 4K's storage and bandwidth burden.
Choosing your retention period
Many jurisdictions and insurance policies require a minimum 30-day retention for commercial CCTV footage, though some regulated industries (banking, cannabis retail) mandate 90 days or longer. Check local regulations before finalizing your drive size, since retrofit expansion later usually costs more than buying adequate capacity upfront.
Approximate daily storage per camera (24/7, H.265, 15fps)
| Resolution | Bitrate (Mbps) | Daily storage/camera | 30-day storage/camera |
|---|---|---|---|
| 1080p | 2.0 | ~21 GB | ~630 GB |
| 2K | 3.0 | ~31 GB | ~950 GB |
| 4K | 6.0 | ~63 GB | ~1.9 TB |
People also ask
How much storage do I need for 8 cameras at 4K for 30 days?
With H.265 compression at 15fps recording 24/7, expect roughly 15TB for 8 cameras over 30 days; switching to motion-only recording can cut that to around 5TB.
Does H.265+ really save that much storage over H.264?
Yes, H.265+ combines HEVC's baseline efficiency with smart scene-change encoding, often achieving 60-70% storage savings over H.264 in typical scenes with limited motion.
Should I record 24/7 or only on motion detection?
24/7 recording guarantees you never miss an event but costs roughly three times the storage of motion-triggered recording; many commercial sites use 24/7 for liability while residential setups often use motion detection to save cost.
How many days of CCTV footage am I legally required to keep?
Requirements vary widely by jurisdiction and industry — many places default to 30 days for general commercial premises, but banks, casinos, and some regulated retail sectors require 90 days or more, so check local law.
What size hard drive should I buy for a home security system?
For a typical 4-camera 1080p home setup with motion-triggered recording and 30-day retention, a 1-2TB drive is usually sufficient; add more headroom if you're recording continuously or using higher resolution.
Does frame rate significantly affect storage size?
Yes, storage scales roughly linearly with frame rate, so dropping from 30fps to 15fps cuts storage needs nearly in half with minimal impact on typical security footage usability.
Is 4K resolution overkill for most security cameras?
For general area monitoring, 2K or even 1080p is often sufficient, but 4K is valuable at entry points and parking areas where you need to read license plates or identify faces at distance.
What's the difference between NVR and DVR storage needs?
NVRs process IP camera streams with more flexible, often higher, resolution and bitrate options, while DVRs handle analog cameras at generally lower resolutions — but the storage math (bitrate × time) works the same way for both.
Should I use RAID for CCTV storage redundancy?
For business-critical surveillance, yes — a RAID 1 or RAID 5 array protects against drive failure wiping out your entire footage archive, at the cost of some usable capacity for redundancy.
How do I reduce CCTV storage costs without losing coverage?
Combine H.265+ compression, motion-triggered recording during low-traffic hours, and a lower resolution on wide-area cameras while reserving higher resolution for critical entry points — this layered approach often cuts storage needs by more than half.
Three worked examples
Same engine, three different starting points — useful if you want to see how sensitive the answer is before you type your own numbers in.
Example 1: number of cameras 6.24 cameras, resolution "2K (QHD)"
On the lower / more conservative end. 6 2K cameras recording 24/7 with H265 need about 5.78TB for 30 days — a 6TB HDD covers it.
Example 2: number of cameras 8 cameras, resolution "4K (UHD)"
A typical middle-of-the-road setup. 8 4K cameras recording 24/7 with H265 need about 14.83TB for 30 days — a 16TB HDD covers it.
Example 3: number of cameras 10.4 cameras, resolution "4K (UHD)"
On the higher / more demanding end. 10 4K cameras recording 24/7 with H265 need about 19.28TB for 30 days — a 20TB (RAID / NAS array) covers it.
Quick answers about the CCTV IP Camera Storage Calculator
What exactly does the CCTV IP Camera Storage Calculator work out?
Sizing an NVR or DVR hard drive correctly means balancing camera resolution, compression codec, frame rate, recording schedule and how many days of footage you legally or practically need to retain. You enter number of cameras, resolution, compression codec and frame rate (plus 2 more optional details) and the result panel updates straight away, so you can compare two or three versions of the same question in a few seconds.
What do I need before I start?
Only 6 fields: number of cameras, resolution, compression codec, frame rate, recording schedule and retention period. Nothing else is needed and nothing is stored.
How is it calculated — why codec choice changes storage by half or more?
H. The same maths runs inside this page, so hand-checking the result on paper gives you the identical figure.
Why do two calculators give me different answers for cCTV IP Camera Storage?
Recording 24/7 gives complete footage but at roughly three times the storage cost of motion-triggered recording, which typically captures 6-10 active hours per day in a residential or small business setting. Different sites pick different assumptions, so always check which method a calculator states before you trust the gap between two numbers.
What does the "Approximate daily storage per camera (24/7, H.265, 15fps)" table on this page tell me?
It is the reference range this tool works against — 3 rows from "1080p" (2.0) up to "4K" (6.0). Use it to sanity-check whether the number you just calculated sits where you expected it to.
Which resolution should I pick?
The dropdown offers 3 choices — 1080p (Full HD), 2K (QHD) and 4K (UHD). Pick the one that matches your real situation rather than the one you would like to be true; resolution usually moves the final figure more than any other single input, so it is worth running it twice with the option above and below your guess.
Do I have to press a button or reload the page to see the result?
No. CCTV IP Camera Storage Calculator runs completely inside your browser, so the moment you change a value the cards recalculate — there is no submit step, no page reload and no waiting for a server round trip. That also means it keeps working on a weak or intermittent mobile connection.
Is it free, and do you keep what I type?
It is free with no sign-up, no app install and no usage limit. Nothing you enter into CCTV IP Camera Storage Calculator leaves your device — the calculation is JavaScript running locally, so there is no upload of your figures to DrHint or anyone else.
Can I use it on a phone?
Yes — the layout stacks to a single column on small screens and the number fields open the numeric keypad on both Android and iOS. Many people bookmark this page or add it to their home screen and re-open it whenever the question comes up.
Anything to be careful about with the result?
With H. Treat the output as a well-grounded estimate for planning, not as a professional, legal or medical decision on its own.
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