Video & Storage
Video Recording Time Calculator
Turn free storage and a bitrate into recording time - with every step of the formula shown.
Free to useNo sign-up requiredNo watermarkRuns in your browser
Whether it is a phone with 50 GB free, an external SSD for a livestream archive or a recorder attached to a camera, the maths is the same: capacity divided by bitrate. The only catch is the units - storage in bytes, bitrates in bits.
Enter the free space and the bitrate, and this calculator shows the recording time and the storage used per hour and per minute, with the formula worked through using your numbers so you can check it.
How this tool works
Enter the free storage
In MB, GB or TB, as your device or drive reports it.
Enter the bitrate
In Mbps or MB/s, or tap a typical bitrate as a starting point.
Read the recording time
Hours and minutes, plus storage per hour and the write speed your storage needs.
How it works
Recording time = capacity × 8 ÷ bitrate. The × 8 turns bytes into bits, because bitrates are measured in bits per second. With 512 GB and 50 Mbps: 512,000 MB × 8 = 4,096,000 megabits, divided by 50 megabits per second = 81,920 seconds, or 22 hours 45 minutes.
If your bitrate is in MB/s it is already in bytes, so the calculator multiplies it by 8 to get Mbps first. 100 MB/s is 800 Mbps.
Storage per hour is the reverse: bitrate × 3,600 seconds ÷ 8. The write rate in MB/s is the bitrate divided by 8 - the sustained speed your card or drive must keep up with to record without dropped frames.
Common use cases
- Checking how much a phone can still record before a long event.
- Sizing an external SSD for a camera recorder or screen-capture setup.
- Estimating how many days of livestream or lecture recordings a drive will hold.
- Converting a bitrate into GB per hour for a storage budget.
Bitrate to storage, at a glance
| 5 Mbps | 2.25 GB per hour · 444 hours per TB |
|---|---|
| 10 Mbps | 4.5 GB per hour · 222 hours per TB |
| 50 Mbps | 22.5 GB per hour · 44.4 hours per TB |
| 100 Mbps | 45 GB per hour · 22.2 hours per TB |
| 400 Mbps (50 MB/s) | 180 GB per hour · 5.6 hours per TB |
| 800 Mbps (100 MB/s) | 360 GB per hour · 2.8 hours per TB |
Mbps vs MB/s, and GB vs GiB
Video bitrates are quoted in megabits per second (Mbps, lower-case b). Storage is sold in megabytes and gigabytes (MB, GB, capital B). A byte is 8 bits, so 100 Mbps is 12.5 MB/s, and an hour at 100 Mbps is 45 GB. Mixing the two up gives an answer eight times too big or too small.
Cards and drives are labelled in decimal units: 1 GB = 1,000,000,000 bytes. Windows and some other systems count in binary units (1 GiB = 1,073,741,824 bytes) but still label them “GB”, so a 128 GB card shows as about 119 GB. Nothing is missing - it is the same space counted differently. This calculator uses decimal units throughout.
Formula
Recording time (seconds)
capacity (bytes) × 8 ÷ bitrate (bits per second)
Storage per hour
bitrate × 3,600 ÷ 8
Write rate (MB/s)
bitrate (Mbps) ÷ 8
Worked examples
512 GB at 50 Mbps
512 GB × 8 ÷ 50 Mbps = 81,920 seconds - about 22.76 hours, or 1,365 minutes. Each hour uses 22.5 GB, and the drive must write at least 6.25 MB/s.
2 TB SSD at 100 MB/s
100 MB/s is 800 Mbps. 2 TB × 8 ÷ 800 Mbps = 20,000 seconds, about 5 hours 33 minutes. Each hour uses 360 GB.
Frequently asked questions
How many hours of video fit in 1 TB?
At 10 Mbps about 222 hours; at 50 Mbps about 44 hours; at 100 Mbps about 22 hours. Divide 2,222 by your bitrate in Mbps for a quick answer.
Why multiply by 8?
Storage is measured in bytes and bitrates in bits. There are 8 bits in a byte, so capacity in bytes × 8 gives capacity in bits, which can then be divided by bits per second.
Does audio change the result?
A little. Typical compressed audio is a few hundred kilobits per second, small next to most video bitrates. Uncompressed multi-channel audio is larger; add it to the bitrate if you record it.
Why is my real recording time different?
Variable-bitrate recording uses fewer bits on simple scenes, so you may get more time. Devices also reserve space and split files, and some stop at a clip-length limit. Keep a margin rather than filling storage completely.