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Storage capacity calculators

Estimate what fits in a drive, work out usable RAID capacity after redundancy, and find the best-value product for your budget — all from live data.

What-fits estimatorRAID 0/1/5/6/10Budget finder
Three working calculators

Three tools to plan storage properly: a ‘what fits’ estimator that turns terabytes into real-world photos, videos, songs and games; a RAID usable-capacity calculator that shows how much space you actually keep after redundancy across RAID 0, 1, 5, 6 and 10; and a budget-to-capacity finder that searches our live catalog for the best-value product that fits your budget and use case. All three run entirely in your browser.

1. What fits in your storage?

Enter a capacity to see roughly how much real-world content it holds. Estimates use typical file sizes; your mileage varies with quality and format.

Assumptions: photo (JPEG) 5 MB · RAW photo 30 MB · song 8 MB · 1080p video 3 GB/hr · 4K video 22 GB/hr · modern game 80 GB · document 0.5 MB.

2. RAID usable-capacity calculator

RAID trades raw capacity for redundancy or speed. Enter your drives to see usable space, fault tolerance and efficiency.

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Usable capacity
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Drives can fail
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Efficiency

3. Budget → capacity finder

Tell us your budget and what the storage is for. We’ll search the live catalog for the best-value product that fits — the most capacity, or lowest $/TB, your money can buy.

Before you buy

Calculators — questions answered

How accurate is the ‘what fits’ estimator?+
It uses typical average file sizes, so treat the numbers as solid ballpark figures rather than exact counts. Your real totals depend on resolution, codec, bitrate and quality settings — a phone JPEG is far smaller than a 45-megapixel RAW, and 4K HDR video dwarfs 1080p. The assumptions are listed under the tool so you can sanity-check them against your own files.
Which RAID level should I choose?+
For most home NAS builds, RAID 5 (single parity) balances usable capacity and protection on smaller arrays, while RAID 6 (double parity) is safer for large arrays where rebuilds take a long time. RAID 1 suits two-drive setups; RAID 10 favours performance. RAID 0 has no redundancy — never use it for irreplaceable data. Our RAID guide covers the trade-offs in depth.
Does RAID replace backups?+
No — this is the single most important thing to understand. RAID protects against drive failure and keeps a system online, but it does nothing against accidental deletion, ransomware, fire, theft or a controller fault that corrupts the array. You still need separate backups; see our 3-2-1 backup guide.
Keep going

Related tools & guides

Guide

How much storage do I need?

A fuller framework for sizing your storage.

Guide

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