Sizing Camera Storage for a Trip – A Practical Calculator
How to size the storage
Define the retention window – Decide the oldest footage you will ever need to review after the trip. For a weekend getaway this might be 3 days; for a two‑week road trip, 14 days.
Pick the recording mode – Continuous recording (e.g., 24 h) uses the full bitrate. Motion‑triggered recording only writes when activity is detected and can cut the average bitrate by 60‑80 %.
Get the camera’s average bitrate – The Tapo C120 at 2 K/15 fps with H.265 usually averages ~2 Mbps; the Reolink RLC‑810A at 4 MP/15 fps with H.264 averages ~4 Mbps. (Check the spec sheet for the exact number for your firmware.)
Do the math –
Required GB = (bitrate Mbps × 0.125 GB per Mb) × seconds per day × retention daysExample for a Tapo C120 on continuous mode for 3 days:
2 Mbps × 0.125 = 0.25 GB/h→0.25 GB/h × 24 h = 6 GB/day→6 GB × 3 days = 18 GB.If you switch to motion‑only and the average drops to 0.5 Mbps, the same 3 day window needs only about 4.5 GB.
Choose the storage medium – Both cameras list microSD compatibility up to 128 GB (UHS‑I U3 class recommended). If the calculated need is ≤ 64 GB, a single high‑quality card is simplest. If you exceed that—say a 14‑day continuous recording for the RLC‑810A (≈ 57 GB/day → ~800 GB total)—consider a portable NVR/SSD that can be swapped after the trip, or a short‑term cloud subscription.
Conditional buying judgment: If your calculation stays under the camera’s maximum card size and you can afford a high‑speed U3 card, go with the card‑only option. If the result is above that limit, pick a USB‑C SSD + a small‑form‑factor NVR (or cloud) as the backup.
Alternative: Cloud storage (often billed per camera per month) eliminates the need to carry cards, but you must have reliable mobile data or Wi‑Fi at the destination and be comfortable with the recurring fee.
Remember to format the card in the camera before use and back up the footage to a laptop or external drive as soon as you return.