Setting Up Your Steam Deck: A Practical Guide
I spent about three weeks last winter trying to figure out exactly how many games I could realistically fit on a 256GB Steam Deck before the thing started choking on its own library. The short version is you can't just guess based on the box sizes listed on the store. Long version, I wrote out a whole system for tracking this stuff, and eventually found the Quick Steam Deck Planner which made my life significantly easier. It is a simple web-based planning tool that lets you add games to a list, see estimated storage sizes, and then cross-reference that against your actual Deck capacity. Nothing fancy. The interface looks like it was built in 2007 and that is honestly part of why it works so well - there are no animations, no login walls, no premium tier gating features that should be free. You open it, type a game name, hit enter, and it pulls approximate file sizes from various community databases and community-reported install data. The developer link is pretty much impossible to find because they never advertise it. Search for "Quick Steam Deck Planner" and the first or second result should be it. If you land on some sketchy mirror site asking for a download, close the tab immediately. The real one is a static HTML page with a JavaScript front end and it requires zero installation.
How It Actually Works in Practice
Here is the workflow I settled on after burning through a few bad approaches. You do not want to just dump every game you own into the planner and hope for the best. The storage estimates are rough - usually within 10 to 15 percent either direction depending on whether a game has lots of language packs or optional texture DLC attached. My method was this. I went through my entire Steam library and filtered out games I had never played more than once, or that I knew I would probably uninstall anyway. Then I added the remaining titles to the planner in groups of about twenty at a time. This took maybe forty five minutes total for a library of roughly two hundred games. The planner then showed me a running total and flagged which entries were pushing past my 64GB microSD card limit. Games that were borderline got the little warning icon next to them, which was actually useful. One thing nobody mentions about this tool is that it does not differentiate between native Steam Deck optimized games and desktop-mode titles. A game like Cyberpunk 2077 running through Proton will show you basically the same file size estimate whether you are running it as a native Linux build or through the compatibility layer. That matters less than you might think since most modern AAA titles on Steam do not have separate Linux builds anyway, but it tripped me up early on when I thought I was saving space by choosing certain games based on supposed Linux compatibility benefits. There were none. Just check your expected file sizes and move on.
The Edge Case That Broke Me for a Day
Here is the specific problem I hit that the official documentation does not cover at all. If you add a game to the planner that you already have installed on your Deck from before you started using it, the planner will still show you the full install size. It does not know about existing installs. I learned this the hard way when I ran a full planning pass and was convinced I needed a 1TB card when I actually only needed 256GB plus my SD slot. I had about forty games already installed that totaled maybe 80GB, and the planner was counting them again on top of everything else. The workaround was brutally manual. I went into my Deck's storage settings and wrote down the exact folder sizes for each pre-existing game. Then I just subtracted those totals from the planner's final count. It took ten minutes and I have never had to do it again because I just make a habit of clearing out the planner list whenever I do a major reinstall. If you are building a fresh setup from zero, this problem does not exist for you at all.
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Common Mistakes People Make
Most users treat the Quick Steam Deck Planner like it is giving them hard numbers. It is not. Those sizes come from aggregated community reports and a handful of community-sourced installation data points. A game listed at 50GB in the planner might actually install at 42GB or 58GB depending on your region, your selected audio languages, and whether any optional DLC got pulled in during a previous install. I stopped treating the numbers as exact and started treating them as directional guidance. You can be off by a few gigabytes here and there without it mattering in the grand scheme. Another mistake is running the planner while your Steam library is in an awkward transitional state. If you just bought a bunch of games on sale and they are sitting in your library uninstalled, the planner counts them as zero size because they are not in any active game list yet. I wasted an evening doing a full planning pass only to realize I had just purchased twelve new games that day and the planner was silently ignoring them. Always make sure your library is fully synced and all purchases have appeared in your library before running a planning session. Steam sometimes takes a while to reflect new purchases, especially on weekends.
When This Tool Completely Fails
The Quick Steam Deck Planner will not help you at all if you are trying to plan around specific performance targets. It gives you storage estimates. It does not tell you whether a game will run well on the Deck's hardware, how much battery it will drain, or what frame rate you should expect. For that you need something else entirely. I use the Steam Deck compatibility category scores from Valve as a quick first pass - games marked as "Verified" are generally safe bets, though there are plenty of verified games that still struggle in demanding scenes, and several Playable-rated games that run perfectly fine on medium settings. The planner also falls apart for retro gaming setups. If you are planning to sideload emulators and run ISOs, the tool has no way to account for that. The file sizes for ROMs and ISOs are so small that it would not meaningfully change your planning numbers anyway, but it also will not remind you that you need extra space for emulator cores and save states across multiple systems. That is just something you need to budget for separately. Leave maybe 2 to 3GB of headroom in your overall plan if you are doing any emulation work.
Bottom Line
The Quick Steam Deck Planner is the kind of tool that looks completely unnecessary until you actually need it. It is ugly, it has no user account system, it probably breaks if Valve changes the structure of their community database, and it will occasionally show you a file size that is off by a couple of gigabytes. But it gets the job done in about fifteen minutes for most people, and it saves you from the more painful alternative of buying games you have no room for and then having to figure out what to uninstall. I have been using it since early 2022 and have recommended it to probably a dozen other Deck owners who were in the same situation I was in back then.
