What does the fleet camera storage calculator estimate?
A vehicle with an MDVR or a multi-channel dashcam records video on an SD card or a hard disk and sends part of it over the mobile network. Three questions come up in every camera project: how large the card or disk must be, how much mobile data each vehicle will use each month, and how much cloud storage the saved clips will take.
This calculator answers all three from the settings of your own device. The on-device storage tab gives the storage needed per vehicle and the next standard card or disk size. The mobile data tab splits monthly data between live view and event clips, for one vehicle and for the fleet. The cloud storage tab sizes the space needed to keep event clips for the number of days you choose.
Why bitrate decides camera storage and data
- Storage grows in a straight line with bitrate. Double the bitrate, the channels or the recording hours and you double the gigabytes. Resolution only matters through the bitrate it needs.
- Every channel records on its own. A four-camera vehicle at 1.2 Mbps per channel writes 4.8 Mbps to the card.
- Live view and clips use the mobile plan, not the card. Their cost depends on minutes watched, clip length and how many channels are sent.
- The codec changes the bitrate. H.265 usually needs a lower bitrate than H.264 for similar picture quality. Use the bitrate your device is actually set to.
Inputs you need from your MDVR or dashcam settings
| Input | Where to find it | Tip |
|---|---|---|
| Cameras (channels) per vehicle | Installation plan | Count every channel that records, including cabin and side cameras. |
| Main-stream bitrate | Device or platform video settings | Per channel, in Mbps. If channels differ, enter their average. |
| Recording hours per day | Shift pattern or ignition hours | Include parking-mode recording if the device records with the engine off. |
| Days to keep before overwrite | Your video policy | The device overwrites the oldest video when the card is full. |
| Live view minutes and sub-stream bitrate | Control room practice and device settings | Live view normally uses the lower-quality sub stream. |
| Event clips, length and channels | Alarm and upload settings | For example, clips sent after harsh braking or a panic button. |
| Cloud retention | Your video policy or contract | How many days uploaded clips stay on the server. |
How fleet camera storage and data are calculated
All sizes are decimal, as printed on SD cards and disks: 1 GB = 1,000 MB and 1 TB = 1,000 GB. Your computer may show the same card as slightly smaller because it counts in binary units.
Converting bitrate to gigabytes
Dividing by 8 turns megabits into megabytes, and dividing by 1,000 turns megabytes into gigabytes. One channel at 1 Mbps records 0.45 GB per hour.
On-device storage
Mobile data per vehicle per month
The clip bitrate is the main-stream bitrate or the sub-stream bitrate, depending on which stream your device uploads. The overhead covers protocol data, GPS messages and retries; it is your assumption.
Cloud storage for retained clips
Clips are only produced on working days, so the retention window is scaled by working days per month over 30. Transfer overhead is not stored, so it is left out here.
Worked example: 20 vehicles with four cameras each
- On-device storage: 1.2 Mbps × 3,600 ÷ 8 ÷ 1,000 = 0.54 GB per channel per hour. With 4 channels for 10 hours a day, each vehicle records 21.6 GB a day. Keeping 7 days needs 151.2 GB; with 10% left free that is 168 GB, so the next standard size is a 256 GB card. It holds 256 × 0.9 ÷ 21.6 = 10.7, so about 10 full days. The 20 vehicles together record about 3 TB over those 7 days.
- Live view: 15 minutes a day of one channel at 0.3 Mbps is 0.3 × 900 ÷ 8 ÷ 1,000 = 0.034 GB (34 MB) a day. Over 26 working days with 5% overhead: 0.92 GB a month.
- Event clips: 5 clips of 30 seconds from 2 channels at the main-stream 1.2 Mbps is 1.2 × 300 ÷ 8 ÷ 1,000 = 0.045 GB (45 MB) a day, or 1.23 GB a month after the same scaling.
- Mobile data: 0.92 + 1.23 = 2.15 GB per vehicle per month, about 43 GB for the fleet. Uploading clips from the 0.3 Mbps sub stream instead would cut the clip data by 75%, saving 0.92 GB per vehicle per month.
- Cloud storage: keeping clips for 30 days needs 0.045 × 26 ÷ 30 × 30 = 1.17 GB per vehicle, or 23.4 GB (0.023 TB) for the fleet.
How to read your results
- Recommended size is the smallest standard card or disk that holds your target days with the headroom you set. A larger size simply keeps video longer before overwrite.
- Days the size holds is what you can promise for investigations. If an incident is usually reported a week later, make sure this figure is above seven.
- Live view share shows where the mobile data goes. When live view dominates, start with a viewing policy before changing device settings.
- The savings table shows what each change saves per vehicle and for the fleet. Use it to agree settings before choosing a data plan.
Common mistakes when sizing dashcam and MDVR storage
- Using resolution instead of bitrate. Two 1080p cameras can differ several times in bitrate. Read the value from the device settings.
- Counting one camera. Storage is per channel; a four-channel MDVR needs four times the space of one.
- Forgetting parking mode. Recording with the engine off adds hours that do not appear in shift times.
- Filling the card to 100%. Formatting and the file system take part of the nominal size, so keep some headroom.
- Planning data for clips only. A few minutes of live view a day can use more data than all event clips.
- Using ordinary SD cards. Continuous recording wears cards out; choose cards rated for continuous video recording by their maker.
Assumptions and limits
Results are estimates. Actual bitrate depends on the device, the codec (H.264 or H.265), the scene, light, motion and the settings, and variable-bitrate modes change from minute to minute. The calculator applies one bitrate to every channel; if your channels differ, enter their average. Mobile data excludes software updates, snapshots and other files the device may send. Cloud storage excludes backups and copies kept by the platform. Check figures against a few days of real recordings before you buy cards or a data plan.