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Dash Cam Storage Calculator — How Much SD Card Space Do You Need?

Find the right SD card size for your dash cam based on resolution, frame rate, and daily driving hours

Total Recording Time

11.5 hrs

Days Coverage

5.8

GB/Hour

10.5

Usable GB

122

Recording Time

11.5 hrs

Days of Coverage

5.8 days

GB per Hour

10.5 GB

Usable Storage

122 GB

Loop Recording

Your card will loop-overwrite oldest footage after 11.5 hours of recording. At your daily driving rate, that’s about 5.8 days before the oldest clip is overwritten.

Frequently Asked Questions

Q

How many GB per hour does a dash cam use at 1080p and 4K?

Storage usage depends on resolution and frame rate. At 1080p/30fps, a dash cam uses about 4–6 GB per hour. At 1440p (2K) it uses 6–9 GB per hour, and at 4K/30fps expect 10–16 GB per hour. Parking mode uses less since many cams drop to lower resolution.

  • 1080p at 30fps: approximately 4–6 GB per hour
  • 1440p (2K) at 30fps: approximately 6–9 GB per hour
  • 4K at 30fps: approximately 10–16 GB per hour
  • Parking mode typically uses 1–3 GB per hour at reduced quality
  • H.265 compression can reduce file sizes by 30–50% compared to H.264
ResolutionGB per HourHours on 128 GBHours on 256 GB
1080p 30fps~5 GB~25 hrs~51 hrs
1440p 30fps~7.5 GB~17 hrs~34 hrs
4K 30fps~13 GB~9 hrs~19 hrs
Q

Is 128GB or 256GB better for a dash cam?

For most single-camera setups, 128 GB is the sweet spot — it holds about 20–24 hours of 1080p footage or 8–10 hours of 4K. If you have a dual-channel (front + rear) setup, drive commercially, or use parking mode, 256 GB is recommended. Cards smaller than 64 GB fill too quickly with loop recording.

  • 64 GB: budget option, holds about 12 hours of 1080p footage
  • 128 GB: best value for most drivers, about 25 hours at 1080p
  • 256 GB: recommended for dual-channel or 4K setups
  • 512 GB: best for commercial drivers or parking mode use
  • Always use a high-endurance micro SD card rated for continuous write cycles
Q

How does loop recording work and does it affect storage needs?

Loop recording overwrites the oldest footage when the card is full, so you never run out of space. However, you still need enough storage to retain recent footage. A 64 GB card at 4K only holds about 5 hours, meaning footage from that morning could be gone by evening.

  • Loop recording automatically deletes oldest files when the card fills up
  • Event-locked files (from G-sensor impact detection) are protected from overwriting
  • More storage means longer retention of potentially important footage
  • With a 128 GB card at 1080p, you retain about 2 full days of driving
  • Parking mode footage competes with driving footage for the same card space
Q

How much extra storage does a front and rear dash cam need?

A dual-channel dash cam (front + rear) roughly doubles your storage usage. If a single 1080p camera uses 5 GB/hr, a dual setup uses about 8–10 GB/hr since the rear camera often records at slightly lower bitrate. Plan for at least 128 GB with dual cams.

  • Dual-channel setups use 1.6–2x the storage of a single camera
  • Rear cameras often record at lower bitrate (e.g., 720p or lower-bitrate 1080p)
  • A 128 GB card holds about 13–16 hours of dual 1080p footage
  • Some 3-channel systems (front, rear, cabin) can use 12–18 GB per hour total
  • Consider 256 GB or larger for any multi-channel configuration

Example Calculations

1Daily Commuter, 1080p Single Cam

Inputs

Resolution1080p
Frame Rate30 fps
Channels1 (front only)
Daily Driving2 hours
Parking ModeOff

Result

Recommended Card64 GB
Daily Usage10 GB
Retention~6 days

At 1080p/30fps with ~5 GB/hr, 2 hours/day = 10 GB/day. A 64 GB card retains about 6 days of footage, which is sufficient for a daily commuter.

2Rideshare Driver, Dual 1080p

Inputs

Resolution1080p
Frame Rate30 fps
Channels2 (front + cabin)
Daily Driving8 hours
Parking ModeOff

Result

Recommended Card256 GB
Daily Usage68 GB
Retention~3.7 days

Dual 1080p at ~8.5 GB/hr combined, 8 hours/day = ~68 GB/day. A 256 GB card provides about 3.7 days of retention, enough to review incidents before overwrite.

34K Enthusiast with Parking Mode

Inputs

Resolution4K
Frame Rate30 fps
Channels1 (front)
Daily Driving3 hours
Parking Mode10 hours at 1080p

Result

Recommended Card256 GB
Daily Usage79 GB
Retention~3.2 days

4K at ~13 GB/hr for 3 hrs = 39 GB driving. Parking mode at 1080p ~4 GB/hr for 10 hrs = 40 GB. Total ~79 GB/day. 256 GB gives ~3.2 days retention.

Formulas Used

Daily Storage Usage

Daily GB = Bitrate (Mbps) × 3600 × Hours / 8 / 1024

Converts video bitrate and daily recording hours into gigabytes of storage consumed per day.

Where:

Bitrate= Video bitrate in megabits per second, determined by resolution and codec
Hours= Total recording hours per day including parking mode

Retention Time

Retention (days) = Card Size (GB) / Daily GB

How many days of footage fit on the card before loop recording starts overwriting.

Where:

Card Size= Total usable capacity of the SD card in gigabytes
Daily GB= Gigabytes recorded per day across all channels

How to Calculate Dash Cam Storage Needs

Choosing the right SD card for your dash cam is crucial. Too small and you lose important footage to loop recording before you can review it. Too large and you overspend on storage you never use.

The main factors are video resolution, frame rate, compression codec (H.264 vs H.265), number of channels, and daily driving hours. A commuter driving 2 hours/day at 1080p needs far less than a rideshare driver recording 10 hours/day at 4K.

This calculator estimates your daily and monthly storage usage, recommends an SD card size, and shows how long your footage will be retained before loop recording overwrites it.

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Last Updated: Mar 9, 2026

This calculator is provided for informational and educational purposes only. Results are estimates and should not be considered professional financial, medical, legal, or other advice. Always consult a qualified professional before making important decisions. UseCalcPro is not responsible for any actions taken based on calculator results.

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