| £/TB | Price | Size | Tech | Form Factor | Condition | Description | Rating | Reviews | |
|---|---|---|---|---|---|---|---|---|---|
 | £33.33 | £99.99-8.3% 24h | 3 TB | HDD | External | New | ★★★★½ 4.6 | 1,084 | |
 | £50.00 | £150.00 | 3 TB | HDD | External | New | ★★★★☆ 4.4 | 1,775 | |
 | £59.14 | £177.41 | 3 TB | HDD | External | New | ★★★★☆ 4.4 | 2,481 | |
 | £61.67 | £185.00 | 3 TB | HDD | External | New | ★★★★☆ 4.0 | 77 | |
 | £72.00 | £215.99-1.3% 24h | 3 TB | HDD | External | New | ★★★★½ 4.5 | 9,151 | |
 | £85.69 | £257.08 | 3 TB | HDD | External | New | ★★★★☆ 4.0 | 207 | |
 | £94.47 | £283.41 | 3 TB | HDD | External | New | ★★★★½ 4.5 | 1,307 | |
 | £101.38 | £304.15+0.5% 24h | 3 TB | HDD | External | New | ★★★★½ 4.6 | 13,882 | |
 | £103.79 | £311.36-0.9% 24h | 3 TB | HDD | External | New | ★★★★☆ 4.4 | 2,227 | |
 | £278.91 | £836.74 | 3 TB | HDD | External | New | ★★★★☆ 4.3 | 217 |
3TB external hard drives: an awkward size worth checking twice
3TB external sits in a gap in the market. It was a mainstream size a decade ago, so plenty of people are replacing one — but manufacturers now jump from 2TB to 4TB, which means the 3TB listings that remain are a short list and are frequently worse £/TB than a 4TB drive costing only a few pounds more. The table above ranks every 3TB external drive we track by real cost per terabyte, so you can see immediately whether today's 3TB price is genuinely competitive.
- Portable 3TB HDD: bus-powered, no mains adapter — Seagate Expansion Portable and similar. The most common 3TB external by far.
- Desktop 3TB HDD: increasingly rare new; if you find one, check it against a 4TB desktop drive on £/TB before buying.
- 3TB external SSD: effectively doesn't exist — SSD capacities go 2TB then 4TB. If speed matters, compare 2TB and 4TB SSDs instead.
Because the choice here is thin, it is worth a deliberate comparison: see all 3TB drives including internal models, all external drives, or step up to 4TB external, which is usually the better buy per terabyte. If you only need it occasionally in a bag, our portable drives page filters to bus-powered models. Our external vs internal guide covers when the USB enclosure is worth paying for, and price per terabyte explained shows why a 4TB drive so often beats a 3TB one on value.
Frequently asked questions
How does disks.co.uk rank 3TB external drives?
We rank every 3TB external drives by real cost per terabyte (£/TB) — the live Amazon.co.uk price divided by capacity — so the best value appears at the top. Prices refresh several times a day from Keepa, with 24-hour movement and all-time-low flags.
What is the cheapest 3TB external drives option right now?
The top of the table above is the cheapest of the 3TB external drives by £/TB today. Desktop (mains-powered) external hard drives are usually the cheapest per terabyte; portable bus-powered drives and external SSDs cost more but need no power cable and survive being carried around.
Should I buy an external hard drive or an external SSD?
For backups and media a hard drive gives far more terabytes per pound. Choose an external SSD if you will work directly off the drive (video editing, games), need shock resistance, or want it fast and pocketable — see SSD vs HDD.
Is an internal drive cheaper than an external one at this size?
Often, yes — an external enclosure adds cost. If you can fit a drive inside a PC or NAS, compare the internal listings on the full capacity page before paying for the USB case. If you need plug-and-play on a laptop, Mac or console, external is the right choice.