How Much Do I Need?

Storage Calculator

How much storage do I need?

Enter roughly how many photos, videos and songs you have (or plan to store) and their average size. The calculator adds them up, leaves room to spare, and suggests a standard storage size.

Photos

A typical phone photo is roughly 2–5 MB. RAW camera files are often 20 MB or more.

Videos

Phones typically record roughly 60–130 MB per minute of 1080p video and 170–400 MB per minute of 4K. Multiply by your usual clip length.

Music and other files

A 3½-minute song is about 3.4 MB at 128 kbps and 6.7 MB at 256 kbps.

Documents, apps, games or anything else, as one total.

Free space

Full drives and phones slow down and can’t install updates. Keeping 10–20% of the drive free is a common target.

Results update as you type.

Your estimate

Storage to get

64 GB

Your files total 30 GB. With 20% of the drive kept free you need 37.5 GB.

Suggested storage

Suggested size
64 GB
Space needed with 20% of the drive free
37.5 GB
Windows shows 64 GB as about
59.6 GB

Calculated total (no free space)

Photos (5,000 × 3 MB)
15 GB
Videos (100 × 150 MB)
15 GB
Total in MB
30,000 MB
Total in GB
30 GB
Total in TB
0.03 TB
How this was calculated
  1. Photos = 5,000 × 3 MB = 15 GB
  2. Videos = 100 × 150 MB = 15 GB
  3. Songs = 0 × 7 MB = 0 KB
  4. Total = photos + videos + songs + 0 KB other = 30 GB
  5. With 20% of the drive kept free = 30 GB ÷ 0.8 = 37.5 GB
  6. Smallest common size that fits = 64 GB
  • Sizes here use decimal units (1 GB = 1,000 MB), as drive and phone makers do. Windows counts 1 GB as 1,073,741,824 bytes, so it shows the same data as a slightly smaller number.
  • A backup drive needs at least as much space as everything it backs up, plus room for older versions if your backup software keeps them.

How the storage calculation works

  1. For each type of file, space = number of files × average size.
  2. Total = photos + videos + songs + other files.
  3. Allow for free space: total ÷ (1 − free space ÷ 100). To keep 20% of a drive empty, your files can fill only 80% of it, so the drive must be total ÷ 0.8.
  4. Suggested size = the smallest common capacity (16 GB, 32 GB, 64 GB … 1 TB, 2 TB and so on) that holds the total with free space.

Finding your average file sizes

File sizes vary a lot with the camera, resolution and format, so the defaults are only a starting point. For a better estimate, look at a few of your own files. On a computer, select a folder of typical photos and check its total size, then divide by the number of files. Phones and cloud services usually show how much space photos and videos take up in their storage settings.

  • Photos: a typical phone photo is roughly 2–5 MB. Newer phones with very high-resolution modes, and RAW files from cameras, can be 20–50 MB or more.
  • Video: size depends on length, resolution, frame rate and format. Phones typically use roughly 60–130 MB per minute at 1080p and 170–400 MB per minute in 4K.
  • Music: at 256 kbps, a minute of audio is about 1.9 MB; at 128 kbps, about 1 MB.

MB, GB and TB: decimal and binary

This calculator uses decimal units, the same way storage makers label their products: 1 KB = 1,000 bytes, 1 MB = 1,000 KB, 1 GB = 1,000 MB and 1 TB = 1,000 GB. Windows uses binary units (1 GB = 1,024 × 1,024 × 1,024 bytes) but still labels them "GB", which is why a new 1 TB drive shows as about 931 GB. The drive isn't missing space. It's the same amount counted differently. Devices also reserve some space for their system software and formatting, so the usable space is always a little less than the number on the box.

Rounding rules

  • The suggested size is the next common capacity at or above your total plus free space. It is never rounded down.
  • Totals are shown in MB (whole numbers), GB (two decimals) and TB (three decimals).