How this security camera storage calculator works
A camera writes video at a fixed rate, so your storage lasts for the size of the card divided by that rate. Everything else on this page is that one sum, projected or solved backwards.
The hard part is the rate. It is called the bitrate, measured in kbps, and it decides how many gigabytes an hour of footage weighs.
Camera makers publish resolution, frame rate and video codec, then stop. Reolink support says it outright: the maximum bitrate differs between models, so go and read it off your own camera.
That is why every other calculator asks you for a figure in Mbps. It is also why most people using one type in a guess.
This tool holds the published specification for 45 cameras and works the bitrate out from it, with one documented rule for every model. Where a real measurement exists it uses that instead, and the camera row tells you which of the two you are looking at.
Why the numbers here run slightly low
Everything is in decimal gigabytes, where 1 GB is a thousand million bytes. That is how memory cards, hard disks and mobile data packs are sold.
Vendors are not always consistent about this. One popular support page works out 582 hours of recording for a 256 GB card, which only holds if you quietly treat that card as 256 binary gigabytes.
This tool does not do that. Its answers run a little lower and a lot closer to what you will actually see on the camera.
How much data does a security camera use?
A 1080p camera writes about 922 MB an hour at 2 Mbps, which is 22 GB a day if it never stops. A 4K camera at 8 Mbps writes 88 GB a day.
Those figures are the same whether the video lands on a microSD card, on a hard disk inside an NVR, or on somebody else’s server.
| Camera | Bitrate | Per hour | Per day, around the clock | Per month, on motion |
|---|---|---|---|---|
| 720p | 1,024 kbps | 461 MB | 11 GB | 5.8 GB |
| 1080p | 2,048 kbps | 922 MB | 22 GB | 12 GB |
| 2K | 3,072 kbps | 1.4 GB | 33 GB | 18 GB |
| 4K | 8,192 kbps | 3.7 GB | 88 GB | 47 GB |
One camera, H.264, motion figures at 25 minutes of recording a day. Decimal GB, the way cards and data packs are sold.
Two things in that table surprise people. The first is the price of 4K: on its own it fills a 1 TB disk in under a fortnight.
The second is how cheap motion recording is by comparison. The gap between those two columns is not a few percent, it is a factor of fifty.
Consumer Wi-Fi cameras sit at the lower end of these figures, because every frame has to cross a home network and usually an upload link as well. A PoE camera wired into a recorder has no such worry and runs at the top of the range.
How long will a 128GB SD card last on a security camera?
About 5 days at 1080p recording around the clock, 3 and a half days at 2K, and a little over one day at 4K. Switch the same 2K camera to motion recording and that card holds months.
The table below is one camera on one card. Two cameras sharing a recorder halve every number, four cameras quarter it.
| Card | 1080p, all day | 2K, all day | 4K, all day | 2K, on motion |
|---|---|---|---|---|
| 32 GB | 1.3 days | 22 hours | 8 hours | 52 days |
| 64 GB | 2.7 days | 1.8 days | 16 hours | 103 days |
| 128 GB | 5.4 days | 3.6 days | 1.3 days | 207 days |
| 256 GB | 11 days | 7.2 days | 2.7 days | Over a year |
| 512 GB | 22 days | 14 days | 5.4 days | Over a year |
H.264, 93 percent of the card usable once the camera has formatted it and kept its loop space free.
A 128 GB card is the size most cameras are sold with. Plan around that five day figure: go away for a week with a camera recording continuously, and the first day or two is already gone before you land.
Check the ceiling before you buy a bigger card
TP-Link publishes 512 GB for the Tapo C210, C310 and C320WS. Reolink states 256 GB across its PoE range, and Wyze supports 256 GB in exFAT on most models with 512 GB on the Cam v4.
A card above the stated maximum sometimes formats happily and then drops recordings weeks later. That is a miserable fault to diagnose, because the app keeps insisting everything is fine.
Is 1TB enough for a 4 camera CCTV system?
A 1 TB disk holds about a week of four 2K cameras recording around the clock. Four terabytes takes the same system to roughly a month.
A recorder changes the arithmetic in one way only: every camera shares the same disk. Disk size stops being a per camera number and becomes a budget divided between them.
| Disk | 2 cameras | 4 cameras | 8 cameras |
|---|---|---|---|
| 1 TB | 14 days | 7.2 days | 3.6 days |
| 2 TB | 29 days | 14 days | 7.2 days |
| 4 TB | 57 days | 29 days | 14 days |
| 6 TB | 86 days | 43 days | 21 days |
| 8 TB | 115 days | 57 days | 29 days |
2K cameras recording around the clock on H.264. H.265 roughly doubles every number.
Four cameras on a 1 TB disk is the common Indian install, and a week of history is usually a surprise to whoever bought it. The box does not mention it.
Use a surveillance rated drive rather than a desktop one. A WD Purple or a Seagate SkyHawk is specified for a write that never stops, which is exactly what a DVR does to it.
Continuous, motion only, or a schedule
This single setting changes your answer more than resolution, codec and card size put together. Around the clock recording writes 86,400 seconds of video a day.
A moderately busy front door on motion detection writes about 1,500 seconds. That is the factor of fifty in the table above.
When continuous recording is worth it
Continuous answers questions motion recording cannot. It shows the gap between two clips, and it survives someone walking in from an angle the sensor never covered.
For a shop counter, a reception area or a gate onto a road, that timeline is worth the disk it costs.
When motion only is the right answer
For a hallway, a bedroom or a driveway that sees a dozen events a day, continuous recording is mostly a very long film of nothing.
Motion recording with sensible detection zones gives you the same evidence and months of history instead of days.
A schedule sits between the two and is underrated. Recording continuously from 10pm to 6am and on motion the rest of the day covers the hours that matter at a third of the storage.
Does H.265 really halve the storage?
Close to it: H.265 stores the same picture in roughly half the space, and this tool uses 55 percent as the conservative figure. Even at 55 percent, a 2K camera that filled a 128 GB card in three and a half days stretches past six.
If your camera offers H.265, also called HEVC, and everything you watch footage on can decode it, switching is the cheapest storage upgrade there is. No new card, no lower resolution, no fewer frames.
The catch is playback. Older phones, some browsers and plenty of budget recorders either refuse H.265 or fall back to software decoding that stutters.
Xiaomi and Imou cameras sold in India ship on H.265 already. Tapo, Wyze and Ring cameras are H.264 throughout, so for those the switch is not on the table at all.
Change the setting, then check you can still play a clip back on the phone you would actually reach for in a hurry.
Does a security camera use upload or download speed?
Upload, which is the direction most home broadband is weakest in. A connection sold as 100 Mbps often carries 5 or 10 Mbps upward, and your cameras have to share that.
| Cameras | 1080p | 2K | 4K |
|---|---|---|---|
| 1 | 2.9 Mbps | 4.4 Mbps | 12 Mbps |
| 2 | 5.9 Mbps | 8.8 Mbps | 23 Mbps |
| 4 | 12 Mbps | 18 Mbps | 47 Mbps |
| 8 | 23 Mbps | 35 Mbps | 94 Mbps |
Upload, not download, and with 30 percent left over so the rest of the house still works. Cameras that record to a card need this only while someone is watching.
Those figures leave 30 percent of the line free. Planning a connection to the brim is how you get stuttering live view the moment somebody starts a video call.
A camera that records to its own card barely touches any of this. It uploads only while you are watching.
So the same connection that chokes on three cloud cameras will carry a dozen local ones. If upload speed is your constraint, local recording is not a compromise, it is the fix.
How much data does a 4G security camera use in India?
Roughly 1 GB a month if you watch ten minutes of live view a day, and about 7 GB if you watch an hour. Recording to the camera’s own card costs nothing from the pack at all.
A 4G camera at a farmhouse, a site office or a second home has no broadband behind it. Only the parts you watch or upload come out of your data pack.
- Ten minutes of live view a day, at the low bitrate these cameras use, is roughly 1 GB a month.
- An hour a day of live view is closer to 7 GB a month.
- Uploading every motion clip to a cloud plan adds about 3 GB a month on a moderately busy view.
- Setting the same camera to upload continuously would use around 50 GB a month, which is what empties a pack in the first week.
So a modest pack is plenty, as long as the camera records locally and you resist watching the live feed for hours.
If the app offers the choice, set it to open on a still image rather than a live stream. That one setting accounts for a surprising share of the bill.
Is cloud storage cheaper than a memory card?
Almost never, if the camera can record locally. A Ring Home Basic plan passes the price of a 128 GB endurance card inside six months and keeps climbing.
A subscription looks small every month and large every three years, which is exactly how it is designed to look. The chart in the tool above plots all three routes and names the month the lines cross.
Ring Home Basic is 4.99 dollars a month, Blink Basic 3.99, Arlo Secure 7.99 and Nest Aware 10. Prices here were checked in August 2026.
When a plan is the right answer anyway
A plan is correct when the camera has no card slot at all, which is true of every Ring, Arlo and Nest camera in our dataset.
It is also correct when the footage has to survive somebody walking off with the camera. A thief takes the card with it.
What deserves more attention is the middle ground. Blink is the one large brand that saves video free, on a USB drive plugged into a Sync Module, and eufy builds local storage into the camera and asks for nothing monthly.
If avoiding a subscription is the goal, buy the hardware that never needed one. That beats paying for a plan and resenting it.
Can I use a normal microSD card in a security camera?
It will work, and then it will fail quietly. Buy an endurance rated card instead.
A camera is the harshest thing you can do to a memory card. It writes constantly, fills the card, overwrites it, and repeats that for years inside a hot plastic housing.
Ordinary cards are built for photographs, which is a fundamentally gentler life.
- Buy an endurance card. SanDisk Max Endurance and Samsung PRO Endurance are the two lines built for this, and SanDisk publishes hour ratings in the tens of thousands.
- Look for V30 or Class 10 at minimum, so the card keeps up with a 4K write.
- Format the card in the camera, not on a computer. The camera picks the file system it can loop on.
- Treat the card as a consumable. Replace it every few years rather than discovering it failed in the week you needed it.
The failure mode is worth knowing, because it is silent. A worn card records fine, then one clip is missing, then a day is missing, and the app still says everything is working.
If your camera has started skipping recordings and the settings have not changed, suspect the card before anything else.
Why does my camera say the card is full after two days?
Usually because it is recording around the clock at full resolution. A 4K camera writes 88 GB a day, so a 128 GB card really is full inside two days.
A cheap card that has started failing gives the same symptom. If the setting is already motion only, suspect the card.
Six mistakes account for almost every case:
- Recording 4K around the clock. Unless you are keeping evidence for a reason, 2K on motion gives you more useful history for a fiftieth of the space.
- Leaving detection zones unset. A camera pointed at a road records every passing car. Mask the road and it drops from a hundred events a day to ten.
- Buying a bigger card to fix a settings problem. Doubling the card doubles the days. Switching to motion multiplies them by fifty.
- Using a normal microSD card. It works for months, then fails without telling the app.
- Ignoring the stated card limit. An oversized card can format cleanly and misbehave later, which looks like a camera fault rather than a card fault.
- Assuming the cloud plan is a backup. A plan keeps clips for its own window, often 30 or 60 days, and usually only the clips it chose to upload.
The setup that gives the least trouble: a 2K camera, H.265 if everything you own can play it, motion recording with proper zones, and a 128 or 256 GB endurance card.
That combination holds months of history, costs nothing monthly and barely touches your internet. Our Wi-Fi camera guide for Indian homes covers which models do all of that without a subscription.
Frequently asked
Do security cameras use internet when nothing is happening?
A little. Cameras hold a connection open and send small keep alive messages, which is megabytes a month rather than gigabytes. The traffic that matters starts when the camera records, uploads a clip, or streams live to your phone.
What is the largest SD card a Tapo or Reolink camera accepts?
TP-Link publishes 512 GB for the Tapo C210, C310 and C320WS. Reolink support states 256 GB across its PoE range and the E1 line. Older models often cap lower, and a card above the stated maximum can format cleanly and then drop recordings, so check your own model first.
How many cameras can a 10 Mbps upload connection handle?
About two 2K cameras uploading to a cloud plan, or three at 1080p, leaving room for the rest of the house. Cameras that record to a card need the upload only while you are watching, so the same line carries many more of those.
Does this work for a CCTV DVR system as well as Wi-Fi cameras?
Yes. Pick the NVR disk option and set the number of cameras, and the tool divides the disk between them the way a recorder does. PoE and wired CCTV cameras run at higher bitrates than Wi-Fi cameras, which the tool accounts for by camera type.
Why does my camera show less space than the card says?
Two reasons. Cards are sold in decimal gigabytes and reported by devices in binary ones, which costs about 7 percent, and the camera keeps a slice free to loop into. This tool assumes 93 percent of a card is usable, which is why its answers are slightly conservative.
Do battery cameras use less storage?
Far less, because they cannot record continuously at all. A battery camera writes only motion clips, so a card that lasts days on a wired camera lasts months on a battery one. The tool disables continuous recording for battery models and says why.
What happens when the memory card is full?
The camera loops: it overwrites the oldest footage and keeps going. Nothing stops recording and nothing needs deleting. The number this tool gives you is how far back the loop reaches before your oldest clip disappears.
Can I record around the clock on a Ring or Nest camera?
Not on most of them. Ring and Nest cameras are event based and have no card slot, so continuous recording needs a plan tier that supports it, and Nest offers 24/7 history only on wired models with Nest Aware Plus. Local recording is not an option on either.
Does night vision use more storage?
Usually a little less. Infrared night footage is greyscale and lower in detail, so it compresses better than a bright daytime scene. Cameras with a spotlight that record in colour at night are the exception and can run slightly higher than daytime.
Is one big card better than two smaller ones?
One big card, on the camera that matters most. Cards cannot be pooled between cameras, so each camera is limited by its own card, and doubling a card exactly doubles that camera history. Spread your budget by resolution and recording mode instead.