A security camera bandwidth calculator tells you the Mbps each camera uses, the monthly data totals if you stream to the cloud, and the hard drive size needed for 30 or 60 days of footage. The calculation uses camera count, resolution (1080p, 4MP, 4K), codec choice, frame rate, and activity level.
Security Camera Bandwidth Calculator
Estimate the bandwidth, monthly data, and hard drive space your security cameras need. Adjust the inputs and the numbers update instantly.
How the Numbers Work
The calculator uses a baseline of 0.7 Mbps per camera at 720p, 15 fps, H.265 codec. This matches real-world test averages from major brands (Reolink, Hikvision, Dahua, UniFi). Higher resolution multiplies the bitrate by the pixel-count ratio. Higher frame rate scales linearly. Codec choice has the biggest impact: H.265 cuts H.264 bitrate roughly in half, and vendor extensions (Hikvision H.265+, Dahua Smart H.265+) cut it further by 30-50 percent on static scenes.
Recording Mode Impact
24/7 continuous recording (CVR) is the highest storage mode. Motion-only mode typically captures 4-6 hours of footage per day on a residential porch. AI-event mode (modern NVRs) only records when a person or vehicle is detected, which averages around 1 hour per day for most residential setups. Pick the mode that matches your actual use case.
Why Storage Estimates Vary
Real-world storage use depends on scene complexity. A camera pointed at a quiet bedroom uses less storage than one pointed at a busy street. Codec performance also varies: H.265+ saves up to 80 percent on completely static scenes (camera at 3 AM in a dark room) but only 30-40 percent on high-motion scenes. The calculator gives a typical middle-ground estimate.
Recommended Drive Sizes
For typical 8-camera setups at 1080p H.265 with CVR mode:
- 2 TB: 22-28 days retention
- 4 TB: 44-56 days
- 6 TB: 66-84 days
- 8 TB: 88-112 days (about 3 months)
- 10 TB: 110-140 days (about 4 months)
- 16 TB: 176-224 days (about 6 months)