# RAID Calculator — NAS storage & upgrade planner > NAS storage and upgrade planner for various RAID levels and NAS systems. (iPhone/iPad app by Todd Greco.) - Source: https://appshunter.io/ios/app/raid-calculator/id395601653 (this page in markdown: same URL + `.md`) - Developer: [Todd Greco](https://appshunter.io/developer/395601656) - Category: Utilities, Productivity - Price: Free - Age rating: 4+ - Requires: iOS 26.0 · 10 MB - Languages: American English, French (France), German (Germany), Italian, Japanese, Korean, Brazilian Portuguese, Russian, Chinese (Simplified, China), European Spanish and 1 more - Released: 2010-10-07 - Data updated: 2026-10-16 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/raid-calculator/id395601653/reviews.md ## What is RAID Calculator? How much space will you actually get? RAID Calculator answers in seconds, for identical drives in classic RAID and for the mixed drives in a real NAS, whether it runs Synology, Unraid, ZFS, SnapRAID or Btrfs. PLAN YOUR NEXT DRIVE Real NAS boxes rarely hold identical drives. Give each bay its own size, or leave it empty, and see what your system does with them: • Five systems: Synology SHR, SHR-2 and RAID 1, 5 or 6; Unraid; ZFS RAID-Z; SnapRAID; and Btrfs RAID1 • Every drive drawn to scale and split into what it holds: data, parity, a mirror copy, or nothing at all • Unused capacity hatched, with the number spelled out • Biggest Upgrade names the single purchase that unlocks the most space, with one tap to try it • Save your current setup, then see every change compared with it (“+4 TB usable”), and Revert when you’re done • Unraid and SnapRAID put parity on your largest drives automatically • For ZFS, the figure ZFS itself will report, labeled as an estimate • Advice where it matters: SnapRAID’s recommended parity count, and a note on very wide RAID-Z groups • From 2 to 12 bays for Synology, or up to 30 for Unraid, ZFS, SnapRAID and Btrfs RAID1 COMPARE SYSTEMS See your drives under every system at once, most usable space first, with failures tolerated and unused space for each. Tap a system to switch to it and watch the same bays re-split. CLASSIC RAID, INSTANTLY Pick RAID 0, 1, 5, 6, 10, 50 or 60, JBOD, or ZFS RAID-Z1, Z2 or Z3, set from 1 to 24 drives and their size, and the answer is the first thing you see: • Usable capacity, raw capacity and storage efficiency • A drive strip showing which drives hold data, parity or mirror copies, split into groups for nested levels and RAID-Z • How many drives can fail, honest about the cases that depend on which drives fail • The TiB figure most NAS systems will report, and for RAID-Z what ZFS itself will report • A rebuild-risk caution for single-parity layouts on large drives, with a one-tap switch to a safer level when your drives allow it • Invalid setups explain themselves and offer a one-tap fix • Relative speed and availability ratings for every level LEARN AS YOU GO Every RAID level and every NAS system has an info sheet: an overview, pros and cons, and typical uses, plus ratings for RAID levels. RAID-Z and every NAS system also explain how the app calculates them. ON EVERY SCREEN • On iPad, and on iPhone Duo opened in landscape, results sit beside inputs and systems line up side by side • On iPad, up to 30 bays fit on screen • On iPhone Duo, info opens in place of the inputs so the results stay in view • Rotates to landscape on iPhone • Built for iOS 26 with native controls and Liquid Glass • Dark mode, Dynamic Type at every size, and full VoiceOver support that also reads each drive within a group • English, Spanish, French, Italian, Japanese, German, Traditional and Simplified Chinese, Korean, Brazilian Portuguese and Russian PRIVATE BY DESIGN No account, no ads, no tracking, no network connection needed. Every calculation happens on your device. Capacities use standard simplified formulas and don’t account for filesystem overhead, apart from the labeled ZFS estimate. Speed and availability ratings compare RAID levels with each other; they aren’t benchmarks. Not affiliated with or endorsed by Synology Inc. Synology and SHR are trademarks of Synology Inc. Not affiliated with or endorsed by Lime Technology, Inc. Unraid is a trademark of Lime Technology, Inc. ZFS is a trademark of Oracle and/or its affiliates. Not affiliated with or endorsed by Oracle. ## Key features - Calculate usable space for mixed drive sizes - Supports Synology, Unraid, ZFS, SnapRAID, Btrfs - Visualize drive data, parity, and mirror copies - Compare different NAS systems side-by-side - Plan drive upgrades and see space gains - Learn about RAID levels and NAS system pros/cons ## Is RAID Calculator safe? Not enough ratings yet to assess RAID Calculator. ## Is RAID Calculator legit? RAID Calculator appears to be a legitimate app. The AppsHunter Legitimacy Score for RAID Calculator is 90 out of 100 points across 7 verification signals from App Store and developer data. ## Recent user reviews (10 of 19) All indexed reviews: https://appshunter.io/ios/app/raid-calculator/id395601653/reviews.md ### 1/5 — Nothing works *2017-08-03* Horrible, nothing works! **Developer response:** it does now! ### 1/5 — DOES NOT WORK *2017-03-31* DOES NOT WORK **Developer response:** it does now! ### 1/5 — Doesn't work *2016-10-12* Can't select variables. Boat anchor. **Developer response:** ha! it does now! ### 1/5 — Nice idea but doesn't work *2016-04-15* None of the parameters are selectable. It's a boat anchor. **Developer response:** try again. 1.7 fixes all of that ### 1/5 — Unusable in iOS9 *2016-03-04* You are unable to select any configurations in iOS9 making the app pointless. **Developer response:** try again. 1.7 fixes all of that ### 1/5 — Doesn't work *2016-02-10* Can't select any parameters- useless **Developer response:** try again. 1.7 fixes all of that ### 1/5 — Doesn't Work *2015-12-14* Cannot select RAID type, drive size or number of drives. What am I missing? **Developer response:** try again. 1.7 fixes all of that ### 4/5 — Update *2015-12-12* Needs update for iOS 9, nothing works. **Developer response:** try again. 1.7 fixes all of that ### 3/5 — Broken by os9 *2015-12-01* Great app but you can no longer select for the spinning wheel after iOS 9 update. Needs update bad. **Developer response:** try again. 1.7 fixes all of that ### 4/5 — Busted by iOS 9? *2015-09-23* Can no longer select item from spinning dial. **Developer response:** try again. 1.7 fixes all of that ## Frequently asked questions about RAID Calculator ### How does RAID Calculator handle mixed drive sizes? RAID Calculator excels at planning for real-world NAS setups where drives are not identical. You can assign specific sizes to each bay, even leaving them empty, and the app will accurately calculate usable space and data distribution across these mixed drives. ### What NAS systems does RAID Calculator support? RAID Calculator supports a wide range of popular NAS systems including Synology (SHR, SHR-2, RAID 1, 5, 6), Unraid, ZFS (RAID-Z), SnapRAID, and Btrfs RAID1. It also handles classic RAID levels like 0, 1, 5, 6, 10, 50, 60, and JBOD. ### Can I compare different storage configurations with RAID Calculator? Yes, you can see your drives under every supported system at once, sorted by usable space. Tapping on a system allows you to switch to it and observe how the same bays reconfigure, making it easy to compare potential setups. ### Does RAID Calculator offer upgrade planning? Absolutely. The 'Biggest Upgrade' feature identifies the single purchase that unlocks the most space. You can also save your current setup and compare it with proposed changes, seeing exact gains like '+4 TB usable'. ### Is RAID Calculator suitable for beginners? Yes, RAID Calculator includes an 'info sheet' for every RAID level and NAS system, providing an overview, pros and cons, and typical uses. For ZFS and NAS systems, it even explains how the app calculates the results, aiding learning. ### What platforms is RAID Calculator available on? RAID Calculator is built for iOS and is available on both iPhone and iPad. It utilizes native controls and supports features like Dark Mode, Dynamic Type, and full VoiceOver support. ### Does RAID Calculator have ads? No, RAID Calculator is ad-free. The app is designed with privacy in mind and does not require an account or display advertisements. ### How often is RAID Calculator updated? The latest version, 1.7.1, was last updated on October 15, 2026. While specific update frequency isn't detailed, the app has been actively maintained since its release in 2010. ## Version history (last 5 releases) ### 1.7.1 — 2026-10-15 RAID Calculator now speaks Russian, for eleven languages in all. The App Store page now shows the app in your language, too. ### 1.7.0 — 2026-10-14 Built for iPhone Duo, with clearer advice and ten languages. • On iPhone Duo, the closed outer display shows a single column. Opened in landscape, results sit beside inputs with the fold between them, and info opens in place of the inputs so your results stay in view • iPhone now rotates to landscape • The NAS comparison starts once you save your current setup, shows the setup it’s comparing against, and Revert asks first • Advice looks different from errors and offers a one-tap fix, such as “Use RAID 6” or “Use 2 parity drives” • RAID 50 and RAID-Z1 groups too narrow to move up now get the rebuild warning too • VoiceOver says when a setup isn’t valid, and reads each drive within a group • A higher-contrast accent color, darker still with Increase Contrast • At the largest text sizes, the level and unit pickers become menus and the drive size lines up under its label • Compare Systems opens at full height, and says when a system uses all your bays • Now also in German, Traditional Chinese, Simplified Chinese, Korean and Brazilian Portuguese ### 1.2 — 2012-03-12 Added some new hard drive sizes; updated main framework; iOS 5 improvements ### 1.01 — 2010-11-19 Fixed crash bug with iOS 4.2/iPad ### 1.0 — 2010-10-07 No release notes. ## More apps by Todd Greco - [RAID Calc2](https://appshunter.io/ios/app/raid-calc2/id6755641457) - [Wax Wishlist](https://appshunter.io/ios/app/wax-wishlist/id6762526523) All apps by Todd Greco: https://appshunter.io/developer/395601656 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-10-16.*