More than you think, less than you fear. Here's a framework to size storage by use case, the file-size rules behind it, and why you should never plan to fill a drive.
“How much storage do I need?” has a real answer, and it's almost always “more than you think, but less than you fear.” Here's a framework to size it by use case, the file-size rules of thumb behind it, and why you should never plan to fill a drive.
Whatever you calculate, don't buy to exactly fit it. Both SSDs and HDDs want breathing room: SSDs slow down and wear faster when packed near full, filesystems fragment and stall, and you always accumulate more than you expect. The rule of thumb: don't routinely fill past about 80% capacity. So take your real estimate and divide by 0.8 — need 800 GB of stuff, buy 1 TB. Then add for growth.
Storage is unusual among computer parts in that you rarely regret buying too much, and almost always regret buying too little. A processor or graphics card you've outgrown still does its job, just more slowly; a full drive simply stops, forcing an awkward migration or a scramble to delete things you wanted to keep. Add that data only ever accumulates — photos, recordings, downloads and game installs pile up and rarely get cleared — and the case for sizing generously becomes obvious. The framework below is about estimating honestly, then adding margin on top.
Rough averages that make estimating quick: a RAW photo runs 25–50 MB; a minute of 4K video roughly 0.3–0.5 GB (far more for high-bitrate or 6K/8K); a modern game install 80–150 GB; a streaming-quality movie 1–4 GB; a lossless music album several hundred MB. Multiply by how many you keep and you have a real number to plan around.
A worked example shows how fast it adds up. A keen photographer shooting 300 RAW frames a week at 40 MB each generates around 12 GB weekly, or roughly 0.6 TB a year — before edits, exports and backups, which can easily double it. Someone filming 4K video a few hours a month can blow past several terabytes in a year on footage alone. Run your own numbers this way rather than guessing; the totals are usually larger than instinct suggests, which is precisely why people run out of space sooner than they expected.
| User type | What fills it | Sensible target |
|---|---|---|
| General user | Documents, photos, some media | 0.5–1 TB SSD |
| Gamer | 80–150 GB installs, growing library | 1–2 TB+ SSD |
| Photographer | RAW catalog + edits + backups | 2–4 TB working, more to archive |
| Videographer | 4K/6K footage, proxies, projects | Many TB; NAS + archive |
| NAS / home server | Media library, backups for all devices | 8–40 TB+ (with redundancy) |
| Data hoarder | Everything, kept forever | Tens of TB; tape for cold archive |
A general user is well served by a 1 TB SSD — fast, roomy enough for years of documents and photos. A gamer should think in libraries, not single titles: a couple of triple-A games eat a 1 TB drive, so 2 TB or a fast NVMe boot drive plus a bulk SATA drive is the comfortable setup — see our gaming storage guide. A photographer or videographer outgrows internal storage fast; the answer is a working SSD plus bulk HDD archive, as laid out in storage for creators.
Once you're consolidating every device's data, streaming a media library and backing up the whole household, you're in NAS territory — and you size for both capacity and redundancy, since RAID sacrifices some raw space for resilience (our RAID guide covers the math). The dedicated hoarder, archiving tens of terabytes forever, eventually finds LTO tape the cheapest cold tier of all, where media can reach single-digit dollars per terabyte. Used enterprise drives are the other great $/TB lever at this scale.
Capacity isn't only a number — it's also a shape. For a single machine, the simplest answer is one roomy internal drive, ideally an SSD for everyday speed. As your data outgrows the case, an external drive adds cheap bulk and doubles as a backup target. Once multiple devices and people share the same library — or you want it always-on for streaming — a NAS with several drives makes more sense than a drawer of externals, because it pools capacity, adds redundancy, and backs everything up centrally. Let how the data is used, not just how much there is, guide the form factor.
A number people routinely underestimate: every terabyte you keep needs to exist more than once. A proper 3-2-1 plan means at least two extra copies of anything irreplaceable, so your true storage budget is a multiple of your primary capacity, not equal to it. Factor that in from the start — it's far cheaper to plan backup capacity alongside primary storage than to scramble for it after a scare. The good news is that backup copies can live on the cheapest media: bulk HDDs, or tape at scale.
Storage needs only ever rise — cameras gain megapixels, games balloon, libraries accrete. Buying a size up today is usually cheaper than buying twice, and high-capacity drives carry the lowest cost per terabyte anyway, so the sweet spot rewards thinking ahead. Rather than do the arithmetic by hand, feed your photo, video and game counts into our capacity calculator, then compare the drives that fit by real value in the $/TB rankings.
Fast, roomy solid-state for general users and gamers, ranked by real $/TB.
Feed your photo, video and game counts into the calculator, then find the best-value drive.
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