Should I use H.264 or H.265?

H.265 if your cameras and NVR both support it, it cuts storage by roughly 40% with equivalent image quality. Most cameras sold since 2020 support H.265. Check your NVR software compatibility before assuming.

Continuous vs motion recording, which should I choose?

Continuous is safest for compliance and evidence purposes, you never miss anything. Motion-only works well for low-traffic areas (storage rooms, back corridors) but relies on your camera's motion detection being reliable. A common middle ground is continuous at low quality with motion-triggered high-quality recording.

How many days should I keep footage?

30 days is the most common default for home and small business. Some industries (retail, hospitality, aged care) may have specific compliance requirements, check your state regulations or insurer requirements. Longer isn't always better if it means underspec'ing your storage.

Do I need surveillance-rated hard drives?

Yes, for any system you rely on. Surveillance drives (WD Purple, Seagate SkyHawk) are designed for continuous sequential writes, which is exactly what CCTV does. Desktop drives will work initially but have significantly higher failure rates under 24/7 write workloads.

Can I use my existing NAS for CCTV?

Often yes: Synology Surveillance Station and QNAP QVR are popular options. The main constraint is camera licence count (Synology includes 2 free, additional licences are approximately $70 each). Check your NAS CPU can handle the decode load, especially with H.265 and 4K streams.

What about cloud recording or hybrid?

Cloud backup of CCTV is possible but expensive at scale due to upload bandwidth and storage costs. Most systems use local NAS/NVR as primary with optional cloud clip backup for critical cameras only. AU NBN upload speeds make full cloud recording impractical for more than a few cameras.

How does CCTV affect my network?

Each camera is a constant stream. 8 cameras at 4MP H.265 at 15 fps produces approximately 28 Mbps, comfortable on gigabit. At 16 or more cameras or 4K, use a dedicated PoE switch and VLAN to keep surveillance traffic isolated. The bandwidth output from this calculator tells you exactly where you sit.

NVR / CCTV Storage Calculator: How Much NAS Storage Do Your Cameras Need?

This NVR and CCTV storage calculator estimates how much hard drive space your security camera system needs based on camera count, resolution, frame rate, and retention period. Helps you choose the right NAS capacity before you buy.

Planning a CCTV or IP camera system and wondering how much storage you actually need? This calculator gives you a realistic estimate based on your camera count, resolution, recording mode, and retention requirements, plus a suggested drive configuration with RAID.

Most vendor calculators overestimate (they want you to buy bigger). We use conservative, real-world bitrate averages so you get an honest number.

Why CCTV Storage Is Harder to Estimate Than It Looks

Camera manufacturers advertise storage requirements based on best-case conditions: minimum bitrate, motion-only recording, and ideal compression. Real installations run 30 to 60 per cent higher. A 4-camera 4K system recording continuously at 8 Mbps per camera needs roughly 1.0 TB per day, not the 200 to 400 GB a vendor tool might suggest. Get this wrong and your actual retention period drops from 30 days to 12.

Three variables drive most of the variance. First is codec: H.265 (HEVC) roughly halves storage compared to H.264 at the same image quality. Most IP cameras sold after 2020 support H.265. Second is recording mode: continuous recording uses 3 to 5 times more storage than motion-triggered recording in a typical residential setting, though motion-only recording can miss events if detection is misconfigured. Third is retention period: every extra day of retention adds proportionally to total storage requirements.

Choosing the Right NAS for NVR Storage

A dedicated NVR appliance handles simultaneous write from all cameras in hardware, but a NAS offers flexibility for mixed workloads. Home NAS units (Synology DS223+, QNAP TS-264, UGREEN DXP2800) handle 2 to 4 cameras at 1080p without issue. Higher camera counts and 4K resolutions need more than just storage: the NAS needs a fast enough network interface and sufficient I/O throughput to sustain multiple simultaneous write streams. The NVR software (Blue Iris on Windows, Shinobi via Docker, Surveillance Station on Synology) adds its own overhead on top of the raw bitrate.

As a rule of thumb: budget at least 1 TB of NAS capacity per camera per month of retention for 1080p, and 2 to 4 TB per camera per month for 4K. Add a 15 per cent headroom buffer on top of any calculated figure to account for filesystem overhead and operational breathing room.

Camera Configuration

Number of Cameras

Resolution

Codec

Framerate

Recording Mode

Recording Type

Continuous Motion-Only

Motion Activity 50%

50%

Recording Hours/Day

Retention & Redundancy

Retention Period

RAID Level

Headroom Buffer

Usable Storage Required

—TB

includes headroom buffer

Suggested Drive Configuration

—

Use surveillance-rated drives, e.g., WD Purple or Seagate SkyHawk

Raw Capacity Breakdown

—

Total Camera Bandwidth

—

How we calculate storage

Bitrate estimates are based on real-world averages at each resolution and codec, not theoretical maximums. H.265 compression is assumed at approximately 60% of equivalent H.264. Framerate scaling uses proportional adjustment from a 15 fps baseline.

Daily storage formula: (bitrate_Mbps × 3600 seconds × recording_hours) ÷ 8 ÷ 1024 = GB per camera per day

RAID overhead is calculated using standard parity formulas:

RAID 5: raw = usable × n÷(n−1) where n = number of drives
RAID 6: raw = usable × n÷(n−2)
RAID 1 / RAID 10: raw = usable × 2

The headroom buffer accounts for filesystem overhead, drive formatting losses (~7%), and operational breathing room. 15% is the recommended minimum.

These are estimates, actual results vary by camera brand, scene complexity, and NVR software overhead. When in doubt, round up one drive size.

AU IP Camera & NVR NAS Pricing Reference (early 2026)

Popular IP cameras and NAS units for AU home/SOHO CCTV. Prices approximate from Amazon AU, Mwave, and manufacturer AU stores.

Product	Type	AU retail (approx)	Notes
Reolink RLC-810A	4K PoE camera	$80-$100	H.265, 8MP, popular AU choice for Synology/QNAP
Reolink RLC-823A	4K PoE + spotlight	$110-$135	4K with colour night vision
Hikvision DS-2CD2143G2-I	4MP dome	$100-$140	Industry standard: Synology Surveillance validated
Synology DS223J	2-bay NAS (NVR)	$310-$360	2 Surveillance Station licences included
Synology DS425+	4-bay NAS (NVR)	$780-$880	4 licences, handles 6-10 cameras comfortably
QNAP TS-433	4-bay NAS (NVR)	$620-$700	QVR Pro included: 8 free licences
Seagate SkyHawk 4 TB	Surveillance HDD	$140-$165	AU retail, optimised for 24/7 camera writes
Seagate SkyHawk 8 TB	Surveillance HDD	$270-$320	Higher capacity for longer retention

AU Privacy & CCTV Storage Considerations

Home CCTV in Australia is generally legal if cameras are directed at your own property. Recording public spaces or neighbours' property without consent may breach state-based surveillance laws. Key points:

Keep footage retention to what is operationally necessary (14-30 days is typical for home use)
Store footage on-site (NAS) rather than cloud where possible, avoids third-party data handling obligations
If operating CCTV for a business, the Privacy Act 1988 may apply depending on annual turnover and data handling practices

Seagate SkyHawk vs IronWolf for NVR: SkyHawk drives are specifically firmware-tuned for continuous surveillance writes (AllFrame AI technology). IronWolf NAS drives work but SkyHawk is the preferred choice for dedicated NVR builds. Both carry 3-year ACL warranty from AU retailers.

Related Tools & Guides

How Much Storage Does a CCTV System Need? → Best NAS for Surveillance Australia → NAS Surveillance Camera Compatibility Guide → RAID Usable Capacity Calculator → NAS Power Cost Calculator → File Transfer Speed Estimator → All Tools →

Frequently Asked Questions

Should I use H.264 or H.265?

H.265 if your cameras and NVR both support it, it cuts storage by roughly 40% with equivalent image quality. Most cameras sold since 2020 support H.265. Check your NVR software compatibility before assuming.
Continuous vs motion recording, which should I choose?

Continuous is safest for compliance and evidence purposes, you never miss anything. Motion-only works well for low-traffic areas (storage rooms, back corridors) but relies on your camera's motion detection being reliable. A common middle ground is continuous at low quality with motion-triggered high-quality recording.
How many days should I keep footage?

30 days is the most common default for home and small business. Some industries (retail, hospitality, aged care) may have specific compliance requirements, check your state regulations or insurer requirements. Longer isn't always better if it means underspec'ing your storage.
Do I need surveillance-rated hard drives?

Yes, for any system you rely on. Surveillance drives (WD Purple, Seagate SkyHawk) are designed for continuous sequential writes, which is exactly what CCTV does. Desktop drives will work initially but have significantly higher failure rates under 24/7 write workloads. Both are available from Australian retailers including Scorptec, Mwave, and Centre Com.
Can I use my existing NAS for CCTV?

Often yes: Synology Surveillance Station and QNAP QVR are popular options. The main constraint is camera licence count (Synology includes 2 free, additional licences are approximately $70 each). Check your NAS CPU can handle the decode load, especially with H.265 and 4K streams. Purpose-built NVRs handle this better but offer less flexibility for other workloads.
What about cloud recording or hybrid setups?

Cloud backup of CCTV is possible but expensive at scale due to upload bandwidth and storage costs. Most systems use local NAS/NVR as primary with optional cloud clip backup for critical cameras only. AU NBN upload speeds (typical 20 Mbps upload on FTTC/FTTN) make full cloud recording impractical for more than a few cameras, use the bandwidth output above to check your specific setup.
How does this affect my network?

Each camera is a constant stream. 8× 4MP H.265 cameras at 15 fps produce approximately 28 Mbps, comfortable on gigabit. At 16 or more cameras, or with 4K resolution, use a dedicated PoE switch and VLAN to keep surveillance traffic isolated from your main network. The bandwidth output from this calculator tells you exactly where you sit.