Most home systems with four cameras need about 2 to 8 TB of hard drive storage to keep 30 days of video, most small businesses with eight cameras need 6 to 12 TB and larger systems with 16 or more cameras commonly need 16 to 40 TB or more. The exact number depends on resolution, compression, frame rate, whether you record all the time or only on motion and how many days you want to keep. Drives are cheap compared with the value of the footage, so most people are better off choosing more storage than they think they need.
This guide gives a simple formula, a quick-reference table and the cost of storage in a professionally installed system. The figures are estimates for planning, not quotes.
1. The Simple Formula
Video storage depends on bitrate, which is how much data each camera produces each second.
Storage per camera per day (GB) ≈ bitrate in Mbps × 10.8
(That comes from 1 Mbps being about 0.125 MB per second, or roughly 10.8 GB per 24 hours.)
Typical bitrates when recording continuously:
| Camera resolution | Typical bitrate (H.265) | Typical bitrate (H.264) |
|---|---|---|
| 2 MP (1080p) | 1 to 2 Mbps | 2 to 4 Mbps |
| 4 MP | 2 to 3 Mbps | 3 to 5 Mbps |
| 8 MP (4K) | 4 to 6 Mbps | 6 to 10 Mbps |
So a 4 MP H.265 camera at 2.5 Mbps uses about 27 GB per day, or about 810 GB over 30 days. A 4K H.264 camera at 8 Mbps uses about 86 GB per day, or 2.6 TB over 30 days.
Real systems vary with scene complexity, lighting, frame rate and settings. A busy street produces more data than a quiet hallway.
2. Quick-Reference Table (Continuous Recording, 4 MP, Approximate)
The table below assumes 4 MP cameras at about 2.5 Mbps (H.265) and continuous recording.
| Cameras | 14 days | 30 days | 60 days |
|---|---|---|---|
| 4 | 1.5 TB | 3.2 TB | 6.5 TB |
| 8 | 3 TB | 6.5 TB | 13 TB |
| 16 | 6 TB | 13 TB | 26 TB |
| 32 | 12 TB | 26 TB | 52 TB |
With H.264 at about 4 Mbps, multiply by roughly 1.6. With 8 MP 4K cameras at about 5 Mbps, multiply by roughly 2.
Always round up. Drives lose some usable capacity to formatting, and recorders overwrite the oldest video as the drive fills, so the stated retention is a maximum, not a guarantee.
3. What Changes the Number
Recording mode. Continuous recording uses the most space. Motion recording can cut storage by half or more for quiet cameras, but you might miss pre-event video unless pre-recording is enabled.
Frame rate. 30 frames per second uses roughly twice the data of 15. Many security uses are fine at 15 fps, but plate capture and fast action benefit from higher rates.
Compression. H.265 and newer codecs use much less space than H.264, though they need a compatible recorder.
Resolution. Higher resolution costs more storage, so use it where detail matters, at doors, registers, gates and plate lanes.
Smart codec features. Some cameras lower bitrate in static scenes. These can cut storage dramatically but can also reduce detail in busy scenes if poorly tuned.
Audio. Adds a small amount of data, and is regulated more strictly than video. See our legal guide before enabling microphones.
Night mode. Infrared scenes are often noisy and can increase bitrate.
4. How Many Days Do You Need?
7 to 14 days. Minimal. Acceptable for low-risk homes where you check footage frequently.
30 days. A good default for homes, shops and offices. Many insurers, landlords and police requests arrive weeks after an event.
60 to 90 days. For higher-risk businesses, valuable inventory, regulated industries or sites unattended for long periods.
Longer. Possible with large arrays or by exporting key clips to separate storage.
Problems often surface late. A missing deposit, a package that disappears while you travel or a neighbor's question about a car two weeks ago are common examples. A system that overwrites after a week may not have the video you need.
5. What Drives Drive Cost
Surveillance-rated drives are built for continuous writing. In 2026, planning prices for a professionally supplied drive commonly look like this:
| Capacity | Typical drive cost (installed with system) |
|---|---|
| 2 TB | $70 to $130 |
| 4 TB | $100 to $180 |
| 8 TB | $170 to $300 |
| 12 TB | $240 to $420 |
| 16 TB | $320 to $560 |
Prices vary by brand and market. Professional installers often include the drive in a package, and the price difference between a 4 TB and an 8 TB drive is small relative to the total job. Increasing storage is one of the cheapest upgrades in any system.
6. Drive Failure and Redundancy
Hard drives fail. Surveillance drives are rated for 24/7 use and commonly last three to five years, but any drive can fail earlier. If you rely on video for business, insurance or compliance, consider:
RAID. Multiple drives configured so that one can fail without losing data. RAID 1 mirrors two drives. RAID 5 or 6 uses several drives with parity. These configurations raise cost but protect your footage.
Health monitoring. Many recorders alert you to drive errors. Enable alerts and check them.
Scheduled replacement. Replace drives proactively every four to five years.
Offsite backup. Copy important clips to separate storage or the cloud. See our guide to cloud versus local storage.
7. Where the Recorder Lives
Drive life depends on heat, dust and vibration. Place the recorder in a ventilated, locked space, away from direct heat, moisture and foot traffic. A battery backup protects against sudden power loss, which can corrupt the drive. In dusty places such as warehouses and kitchens, use a sealed cabinet with filtered airflow.
News coverage shows how stored video enters investigations. In September 2026, NYPD sought suspects in 19 commercial burglaries across 16 Brooklyn neighborhoods, according to News 12. The article did not mention footage. But when a pattern of crimes spans many locations, businesses that can produce clean video from days or weeks earlier give investigators far more to work with than those whose recorders overwrite quickly.
8. Cybersecurity and Storage
Footage is sensitive. Protect the recorder with strong passwords, keep firmware updated and limit remote access. Do not expose the recorder directly to the internet. The Cybersecurity and Infrastructure Security Agency offers practical guidance on securing connected devices at cisa.gov. Encrypt exports where possible, and store copies of important clips securely.
9. Saving Money Without Short-Changing Storage
- Use higher resolution only where it matters.
- Use H.265 if the recorder supports it.
- Use motion recording for quiet cameras.
- Choose a recorder with spare drive bays for expansion.
- Pick the next size up in drive capacity.
Not sure how much storage you need? Revolvis will walk the property with you and mark the spots.
10. A Worked Example
A Queens restaurant has twelve cameras: four 4 MP at the entrance, bar and register, six 2 MP in the kitchen and storage and two 4 MP outside. The owner wants 45 days of retention. Using H.265, the 4 MP cameras average 2.5 Mbps (27 GB per day each) and the 2 MP cameras 1.5 Mbps (16 GB per day each). Daily total: six 4 MP cameras at 27 GB equals 162 GB, plus six 2 MP cameras at 16 GB equals 96 GB, so about 258 GB per day. Over 45 days: about 11.6 TB. Add a buffer for overhead and variation, and the owner chooses 16 TB in a RAID configuration. A professional installer should show you this math, or give you a storage calculator, before you buy.
11. Questions to Ask
- How many days of footage will the included drive hold at your settings?
- Is the system set to continuous or motion recording?
- Does the recorder support RAID or additional drive bays?
- What happens when a drive fails?
- Can I add storage later?
- How do I export and back up important clips?
See our services page, security camera installation in Brooklyn, commercial installation in Queens and home camera installation in Staten Island.
12. Common Mistakes
Choosing the smallest drive in the box. It often provides only a week or two of video.
Forgetting to set retention. Some recorders overwrite at default settings that do not match your needs.
Recording everything at maximum quality. It wastes space where detail is not needed.
No drive monitoring. Many people do not know a drive has failed until they need the footage.
Putting the recorder where it overheats. Heat shortens life.
Not testing playback. Always check that you can find and export a clip from last week.
More From Revolvis
Cameras are one layer of a secure property. The same in-house crew also handles the rest:
- Keyless entry installation and smart lock installation
- Access control systems and commercial access control
- Video doorbells and intercoms
- Alarm system installation
- Complete unified security
Learn more about Revolvis, meet the team, see all services, browse the blog or contact us.
Areas We Serve
Revolvis installs residential and commercial camera systems across the New York metro area. Every borough and county has its own building stock, rules and wiring challenges, so the plan for a Queens two-family is not the plan for a Manhattan co-op.
- Staten Island: houses, detached garages and shop fronts. See security camera installation in Staten Island.
- Brooklyn: brownstones, row houses and storefronts. See security camera installation in Brooklyn.
- Queens: attached brick homes, two-families and busy commercial strips. See security camera installation in Queens.
- The Bronx: pre-war buildings, bodegas and warehouses. See security camera installation in the Bronx.
- Manhattan: co-ops, condos, offices and retail. See security camera installation in Manhattan.
- Long Island: Nassau County and Suffolk County.
- New Jersey: Jersey City, Newark, Hoboken and nearby towns.
The full list is on the service areas page.
Get a Custom Quote After a Site Visit
Revolvis prices every job after a site visit, because the building sets the cost as much as the equipment does. A few things make the estimate faster and more accurate:
- The address and property type: house, apartment, co-op, condo, storefront or warehouse.
- Which doors, sides and areas you want covered, and what worries you most.
- Photos of those spots and any spots where you already have cabling or power.
- How many days of footage you want to keep and whether you want to watch on your phone.
- Any landlord, board, lender or insurer requirement.
Call 347-258-9165 or use the contact page to book a site visit. The quote you receive is written and itemized, so you can compare it line by line.
Frequently Asked Questions
How much storage do 4 security cameras need for 30 days? About 3 to 6 TB for 4 MP cameras recording continuously, depending on compression and settings.
How much storage do 8 cameras need? About 6 to 12 TB for 30 days with 4 MP cameras recording continuously.
Does motion recording save space? Yes, often by half or more, but you may miss some events if settings are poor.
What type of hard drive should I use? Surveillance-rated drives are designed for continuous recording.
Do I need RAID? For homes, usually not. For businesses that depend on footage, RAID is worth considering.
How often should I replace the drives? Every four to five years is a common rule of thumb, sooner if the recorder reports errors.
Ready for a custom quote? Call Revolvis at 347-258-9165 for a site visit and a written, itemized estimate.
Safety note: A camera system supports, but does not replace, good locks, lighting, alarms and everyday habits. If you are in danger or witnessing a crime, call 911. Prices and legal summaries in this guide are general information for the New York metro area, not an offer or legal advice. A written quote after a site visit governs your actual price, and for legal questions you should confirm with the agencies linked in the article or a licensed attorney.