The starting point
Check three things independently: how much video the drives can keep, how many cameras the recorder supports, and whether the switch can power the complete system. Passing one check does not mean the others pass.
1. Start with what the footage needs to show
List the entrance, room or exterior area each camera should cover. Describe the event you want to review and the level of detail you need. A wide overview and a useful close view at an entrance are different goals. Resolution alone does not decide placement, lighting or the result.
Next, set a retention target and decide whether recording should be continuous or event based. The examples below use explicit average bitrates and recording activity. They are planning calculations, not measured installations or promises of a fixed retention period.
2. Three camera plans, with the working shown
Each example uses the same calculation rules as our system builder. Equipment names identify the specifications being compared; the room or building type is an illustrative setting, not a completed client project. Prices and installation allowances are excluded.
Planning example 01 · Home or small business planning example
How much storage do eight 4K security cameras need for 30 days?
At an assumed average of 8 Mbps each, eight 4K cameras recording continuously need 20.736 TB for 30 days. Four 8 TB drives in RAID 5 provide 21.6 TB after a 10% planning reserve—about 31.25 days under these assumptions.
- Recording for 30 days
- 20.736 TB
- Usable after RAID + reserve
- 21.6 TB
- Modeled retention
- 31.25 days
The plan and its assumptions
- Camera mix
- 8 × UniFi G6 Turret (4K)
- Average recording bitrate
- 4K: 8 Mbps each
- Recording and target
- Continuous, 100% duty fraction; 30 days at the assumed bitrate
- Recorder and drives
- 1 × UniFi UNVR; 4 × 8 TB equal-size compatible drives per recorder; RAID 5
- Storage reserve
- 10% after RAID protection; decimal TB
- Switch and power
- 1 × UniFi Pro 24 PoE · 24 PoE / 400W; 100 W device maximums + 20% headroom = 120 W
- Other connections
- No extra PoE or wired devices; 2 spare RJ45 ports plus recorder and uplink capacity reserved
- Mounting assumption
- 6U of available existing rack space; depth, load and ventilation still need review
Follow the calculation
- 8 × 8 = 64 Mbps average total recording rate.
- 64 × 86,400 ÷ 8 ÷ 1,000,000 = 0.6912 TB per day; × 30 = 20.736 TB of recordings.
- (4 − 1) × 8 TB × 0.9 = 21.6 TB usable after RAID 5 and reserve. Raw capacity is 32 TB.
- 21.6 ÷ 0.6912 = about 31.25 days, assuming the recording settings allow footage to remain that long.
Camera resolution alone cannot tell you retention. Bitrate, recording hours, drive protection and reserve all change the answer. This example has limited margin above 30 days; higher bitrate requires more storage.
Product references: UniFi G6 Turret · 4K / 12.5W PoE specifications · UniFi UNVR specifications · Ubiquiti: RAID and storage protection · Ubiquiti: storage and retention settings · UniFi Pro 24 PoE · 24 PoE / 400W specifications
Planning example 02 · Multifamily or commercial planning example
Can one recorder handle a mix of 2K and 4K cameras for 30 days?
For 12 cameras at 2K and eight at 4K, our UNVR capacity ratio is 84.44% using Ubiquiti’s published camera counts. At assumed averages of 4 and 8 Mbps respectively, four 16 TB drives in RAID 5 give about 35.71 days after a 10% reserve. Four 8 TB drives give only 17.86 days with the same cameras.
- Recording for 30 days
- 36.288 TB
- Usable after RAID + reserve
- 43.2 TB
- Modeled retention
- 35.71 days
The plan and its assumptions
- Camera mix
- 12 × UniFi G5 Turret Ultra (2K); 8 × UniFi G6 Turret (4K)
- Average recording bitrate
- 2K: 4 Mbps each; 4K: 8 Mbps each
- Recording and target
- Continuous, 100% duty fraction; 30 days at the assumed bitrate
- Recorder and drives
- 1 × UniFi UNVR; 4 × 16 TB equal-size compatible drives per recorder; RAID 5
- Storage reserve
- 10% after RAID protection; decimal TB
- Switch and power
- 1 × UniFi Pro 24 PoE · 24 PoE / 400W; 148 W device maximums + 20% headroom = 177.6 W
- Other connections
- No extra PoE or wired devices; 1 spare RJ45 port plus recorder and uplink capacity reserved
- Mounting assumption
- 6U of available existing rack space; depth, load and ventilation still need review
Follow the calculation
- Our mixed-camera capacity ratio: (12 ÷ 30 + 8 ÷ 18) × 100 = 84.44%. This is a planning ratio, not measured processor load.
- 12 × 4 + 8 × 8 = 112 Mbps average total recording rate.
- 112 × 86,400 ÷ 8 ÷ 1,000,000 = 1.2096 TB per day; × 30 = 36.288 TB of recordings.
- (4 − 1) × 16 TB × 0.9 = 43.2 TB usable after RAID 5 and reserve. Raw capacity is 64 TB.
- 43.2 ÷ 1.2096 = about 35.71 days, assuming the recording settings allow footage to remain that long.
Check recorder capacity and storage separately. Passing the camera-count check does not establish a 30-day recording history.
Same recorder and cameras, four 8 TB drives
That smaller drive layout has 21.6 TB usable and about 17.86 days of modeled retention. Recorder capacity still passes, but the 30-day storage target does not.
Product references: Ubiquiti: recommended camera capacity · UniFi G5 Turret Ultra · 2K / 4W PoE specifications · UniFi G6 Turret · 4K / 12.5W PoE specifications · UniFi UNVR specifications · Ubiquiti: RAID and storage protection · Ubiquiti: storage and retention settings · UniFi Pro 24 PoE · 24 PoE / 400W specifications
Planning example 03 · Four-camera small-site planning example
Why can a PoE switch with enough ports fail a camera power check?
Four G6 Turret cameras have a combined maximum of 50 W, or 60 W with our 20% planning headroom. A Standard 16 PoE switch has 8 PoE ports but only a 42 W total budget, so the ports fit and the power does not. A Standard 24 PoE’s 95 W budget passes this example’s power check.
- Camera maximum power
- 50 W
- With 20% headroom
- 60 W
- Undersized switch budget
- 42 W
The plan and its assumptions
- Camera mix
- 4 × UniFi G6 Turret (4K)
- Average recording bitrate
- 4K: 8 Mbps each
- Recording and target
- Continuous, 100% duty fraction; 30 days at the assumed bitrate
- Recorder and drives
- 1 × UniFi UNVR; 3 × 8 TB equal-size compatible drives per recorder; RAID 5
- Storage reserve
- 10% after RAID protection; decimal TB
- Switch and power
- 1 × UniFi Standard 24 PoE · 16 PoE+ / 95W; 50 W device maximums + 20% headroom = 60 W
- Other connections
- No extra PoE or wired devices; 2 spare RJ45 ports plus recorder and uplink capacity reserved
- Mounting assumption
- 6U of available existing rack space; depth, load and ventilation still need review
Follow the calculation
- 4 × 12.5 W = 50 W of maximum camera demand; × 1.2 = 60 W with planning headroom.
- 8 PoE ports cover four cameras, but 60 W exceeds the Standard 16 PoE’s 42 W budget. Even the camera maximums alone exceed it.
- The illustrated Standard 24 PoE has 16 compatible PoE ports and a 95 W budget. Its port count and power budget both pass this four-camera example.
- 4 × 8 = 32 Mbps average total recording rate.
- 32 × 86,400 ÷ 8 ÷ 1,000,000 = 0.3456 TB per day; × 30 = 10.368 TB of recordings.
- (3 − 1) × 8 TB × 0.9 = 14.4 TB usable after RAID 5 and reserve. Raw capacity is 24 TB.
- 14.4 ÷ 0.3456 = about 41.67 days, assuming the recording settings allow footage to remain that long.
Read the total PoE budget as well as the port count. Also check each device’s PoE standard and keep allowance for cable losses and future devices.
Product references: UniFi G6 Turret · 4K / 12.5W PoE specifications · UniFi Standard 16 PoE · 8 PoE+ / 42W specifications · UniFi Standard 24 PoE · 16 PoE+ / 95W specifications · UniFi UNVR specifications · Ubiquiti: RAID and storage protection · Ubiquiti: storage and retention settings
3. What changes camera storage and retention?
The storage calculation starts with average recorded bitrate, not resolution by itself. Multiply the combined megabits per second by the recording time, then convert bits to bytes. Our examples use decimal terabytes: 1 TB is 1,000,000,000,000 bytes. A drive or operating system may display capacity using different units.
An assumed 8 Mbps per 4K camera is a modeling input, not a manufacturer promise. Scene motion, image settings, frame rate, codec, lighting and recording mode can change the average. Check real recordings after installation and adjust the plan when they differ from the assumption.
Event recording can reduce recorded time, but the saving depends on what happens at the property and how recording is configured. A quiet doorway and a busy loading area will behave differently. Continuous recording at the stated average bitrate is the basis of all three examples here.
Raw drive capacity is not all available for footage. Drive protection and the planning reserve reduce it before retention is calculated. These examples reserve 10% after protection; that is our planning allowance, not a claim about an exact amount reserved by the recorder.
Product reference: Ubiquiti: Managing Storage and Retention in UniFi Protect
4. Recorder camera limits are a separate check
A recorder can have enough disk space and still be the wrong choice for the camera mix. Supported camera limits concern the recorder’s workload; retention concerns the volume of video written to its drives. Adding drives does not, by itself, raise the supported camera limit.
For mixed resolutions, the planner uses a proportional load estimate: the count in each resolution group divided by that recorder’s published limit for the group, added together. This is a planning approximation. It does not certify a mixed-camera deployment or replace the manufacturer’s guidance for the exact devices, software and features.
Leave room for planned additions and review resource-intensive features before final equipment selection. Recheck current product limits and drive compatibility when ordering. A result below 100% in an example is one check in the design, not approval of the complete installation.
Product reference: Ubiquiti: UniFi Protect Supported Camera Limits
5. Enough PoE ports can still mean too little power
Check the power standard and per-port capability required by each camera, then add the selected devices’ maximum rated power. Compare that load with the switch’s total available PoE budget. Ethernet port count, PoE port count and available watts describe different limits.
Our examples add 20% headroom to the rated device load. This is a stated planning choice, not a manufacturer requirement. Include other powered equipment sharing the switch: access readers, Wi-Fi access points and future devices all need their own allowance.
The small-site example shows why counting ports can mislead: the compared 16-port switch has enough PoE ports for four cameras, yet its 42 W budget is below their combined 50 W rated load, before headroom. Review cable runs, suitable power supplies and the exact switch model as part of the installation design.
Product reference: Ubiquiti: PoE Availability and Modes
6. Drive protection is not a backup
Protection uses part of the installed capacity to tolerate a specified drive failure. The four-drive RAID 5 examples use three drives’ worth of capacity before the planning reserve. The three-drive example uses two drives’ worth. A single unprotected drive would not provide that redundancy.
Drive protection does not replace a backup or protect against every cause of footage loss. Decide who can export footage, where an authorized export belongs, and how long it should be retained. Confirm the selected recorder’s supported protection modes and drive requirements before purchasing.
Product reference: Ubiquiti: Storage Protection and Data Redundancy in UniFi RAID
7. Turn the calculation into an installation brief
- Mark the required views, proposed camera locations and any privacy-sensitive areas.
- Record exact models, quantities, recording settings, retention target and future additions.
- Confirm recorder capacity, drive compatibility, protection and the storage allowance.
- Check PoE standards, total power, cable routes, mounting and network connections.
- Agree on account ownership, viewing permissions, clip export, outage behavior and handoff tests.
- Ask for a site-specific scope covering cabling, configuration, finish restoration and exclusions.