Ack, no, don't use specialized calculators for this. They are terrible. Learn the basics and calculate it for yourself.
For example using the WD calculator linked above, I put in 1 camera, 1 day of storage, H.264, at 4K resolution and 10 FPS. It said you will need 0.363 TB (or 363 GB). That is so far off it is crazy. I did the math. You'd have to be recording at a bit rate of 33.6 Mbps for that to be accurate.
(0.363 TB / 24 hours) to Mbps - Google Search
Increase the frame rate in their calculator to 30 FPS and now they recommend 1.089 TB, which means a bit rate of 100.8 Mbps. That is just astoundingly unrealistic for an IP surveillance camera.
I give Western Digital a solid
F on their surveillance storage calculator.
So. Here is how to do it right.
To calculate required storage space, you only need to know two things: The average bit rate, and the amount of time. Then multiply them together with Google, being careful to use the correct units. When describing streaming bit rates and network speed, we typically use "bits" per second. Bits is represented by a lower case 'b'. Hard drive capacity is usually discussed in "bytes" abbreviated with a capital 'B'. Don't confuse them. People get this wrong all the time. Even internet providers.
Mbps = megabits per second. Typically used for describing internet and LAN speeds or audio and video bit rates.
MB/s = megabytes per second. Typically used for describing hard drive or SSD speed and file transfer rates.
MB = megabyte (1 million bytes)
Mb = megabit (1 million bits)
1 byte = 8 bits
Anyway,
One 8MP camera at, say, 15 FPS, is going to do just fine between 8 and 16 Mbps bit rate. In fact you might be limited by the camera's encoder and not be able to reach 16 Mbps. Lets assume you use a bit rate of 8 Mbps. Punch that into google and it conveniently gives you the answer in gigabytes.
Correct calculation:
8 Mbps * 1 day
Incorrect calculation:
8 MBps * 1 day
Now you said you are going to use 8 cameras. You can just multiply by 8 to get results for 8 cameras.
8 Mbps * 1 day * 8
Of course 1 day isn't very long. Lets assume you want to record for a week.
8 Mbps * 1 week * 8
You can do other neat things too, like take a hard drive size and divide by a bit rate. Lets assume you have a 6 TB drive.
6 TB / (8 Mbps * 8) = 8.68 days
Of course we all know that formatted, usable capacity is always lower than the advertised capacity. You usually get to store around 90% of the advertised capacity. So we can improve the accuracy of the calculation:
(6 TB * .9) / (8 Mbps * 8) = 7.81 days
