This surveillance and NVR storage calculator estimates total storage required for your security camera system based on camera count, resolution, bitrate, and retention period. Designed for Australian home and small business setups using NAS-based NVR storage.
Enter your camera count, resolution and retention period to get an accurate NAS storage estimate, plus recommended NAS units and surveillance drives.
Frequently Asked Questions
How much storage do I need for 4 cameras at 4K for 30 days?
At 4K with H.264 continuous recording, each camera uses approximately 16 Mbps. Four cameras running 24/7 generate around 864 GB of raw footage per day. For 30-day retention that's about 25 TB raw, or 50 TB with RAID 1 mirroring. Switching to H.265 halves this to around 25 TB with RAID. Motion-triggered recording (assuming 30% duty) reduces it further to roughly 8-9 TB with RAID for 30 days.
What is RAID overhead and why does it double storage?
RAID 1 (mirroring) keeps two identical copies of all data across two drives. If one drive fails, the other keeps your footage safe. The downside is you need twice the raw drive capacity. RAID 5 / SHR use parity instead and are more space-efficient for three or more drives, but for two-drive NAS units (the most common for home surveillance), RAID 1 is the standard choice. If you're using a four-bay NAS in RAID 5, your effective overhead is roughly 1.33×, you can uncheck RAID in the calculator and add ~33% manually.
Does H.265 really halve storage compared to H.264?
In practice H.265 (HEVC) achieves 40-60% better compression than H.264 at the same quality level. Most modern IP cameras support H.265, and Synology Surveillance Station, QNAP QVR Pro and other NVR software handle both codecs. If your cameras and NVR software both support H.265, enabling it is the single biggest way to reduce storage requirements without changing retention or resolution.
What is the Synology camera licence cost?
Synology Surveillance Station includes two free camera licences with every NAS. Additional cameras require a paid licence from the Synology licence portal, typically around AUD $60-70 per camera for a permanent licence. QNAP QVR Pro also includes two free licences. For systems with more than two cameras, factor licence cost into your total budget alongside hardware.
Why does the calculator recommend Seagate SkyHawk over standard hard drives?
Standard desktop drives are designed for sequential reads and writes, not 24/7 continuous write cycles from multiple camera streams simultaneously. Surveillance-optimised drives like the Seagate SkyHawk series are rated for always-on operation, have firmware tuned for high write duty cycles, and are validated to handle up to 64 concurrent camera streams. Using a standard desktop drive for continuous surveillance recording risks early failure and voided warranties.