How Much Space Do macOS Caches Actually Use? We Measured 50 Macs

Published March 2026 · 12 min read · Original research by Intel Systems

Everyone knows Macs accumulate cache files. But how much space do they actually use? We couldn't find any real data on this — just vague estimates like "a few GB" or "it depends."

So we measured it ourselves.

We ran CleanDisk on 50 Macs across a range of users: students, designers, developers, video editors, and general office workers. Every Mac was running macOS 14 or 15, and had been in daily use for at least 6 months without any manual cache cleaning.

Here's what we found.

The data: cache usage by category

CleanDisk scans five categories of reclaimable files. Here's the average, median, and maximum for each across our 50-Mac sample:

The standout finding: creative app caches are by far the largest category — but also the most skewed. If you don't use Adobe Creative Suite, DaVinci Resolve, or Final Cut Pro, your creative cache is likely near zero. If you do, it's often the single biggest source of wasted space on your Mac.

Breakdown: what's in each category

Application caches (avg. 12.1 GB)

Every app on your Mac stores temporary data in ~/Library/Caches/. The biggest offenders we found:

Chrome was the single biggest cache on 34 of our 50 Macs. Electron-based apps (Slack, Teams, Discord) were consistently in the top 5 — their Chromium engine caches web content aggressively.

Creative app caches (avg. 15.3 GB)

This is where the extreme numbers live. Creative apps generate massive temporary files for rendering, previewing, and transcoding:

The key insight: Premiere Pro's Media Cache is the single largest reclaimable item on most creative Macs. It stores transcoded media for playback performance, and it never cleans itself up — even after you delete the original project.

One Mac in our sample had 52.3 GB of Premiere Media Cache from projects that had been deleted months ago. The user had no idea it was there.

Developer tool caches (avg. 8.7 GB)

Only 22 of our 50 Macs had developer tools installed. Among those 22, the average jumped to 19.8 GB:

Xcode DerivedData dominates this category. See our complete guide to DerivedData for a deep dive.

Log files (avg. 1.8 GB)

System and application logs at /Library/Logs/ and ~/Library/Logs/. Not huge, but they accumulate over time. macOS does rotate system logs, but application logs (particularly crash reports) can pile up. One Mac had 8.3 GB of accumulated crash reports from a repeatedly crashing Electron app.

Old downloads (avg. 4.2 GB)

Files in ~/Downloads/ older than 30 days. This is the most subjective category — these aren't really "cache" files, but they're often forgotten. DMG installers were the most common: people download an app, install it, and never delete the installer.

The user profiles

Cache usage varied dramatically by user type:

Video editors had the highest average — not surprising given Premiere and DaVinci's cache behavior. But the single highest total (147.3 GB) was a developer running Xcode, Docker, and three Node.js projects. Their node_modules wasn't included in our scan (it's project data, not cache), but their package manager caches alone were 11.2 GB.

How cache correlates with disk size

We expected Macs with larger disks to have more cache (more room to accumulate). The data partially confirmed this:

The absolute cache size grows with disk size, but the percentage decreases. This makes sense: cache accumulation is driven by app usage, not available space. But here's the critical finding — 256 GB Mac users lost 11.4% of their total storage to cache. On a machine where every gigabyte counts, that's painful.

How fast does cache accumulate?

We asked 10 participants to clear all their caches and then checked again after 30 days. The results:

• After 7 days: Average 8.2 GB accumulated
• After 14 days: Average 16.1 GB
• After 30 days: Average 24.7 GB

Cache accumulates roughly linearly for the first month, then slows as the most active caches hit their internal size limits. The implication: monthly cleaning is a reasonable cadence for most users. If you're on a 256 GB Mac, every two weeks is better.

What's safe to delete?

Not all cache is equal. Here's how we categorize it:

CleanDisk labels every item with one of these three levels. The free scan shows you the labels — you can see exactly what's safe before you decide to subscribe and delete.

Methodology

For transparency, here's how we conducted this analysis:

• Sample: 50 Macs belonging to team members, friends, and volunteers in Oslo, Norway
• Tool: CleanDisk v1.0 (the same build available for download)
• Criteria: macOS 14 or 15, in daily use for 6+ months, no recent manual cache cleaning
• Date: February–March 2026
• Privacy: We recorded only aggregate size data per category. No filenames, paths, or personal data were collected.

This is a small sample and shouldn't be treated as a formal study. But it's real data from real Macs — which is more than most "how much cache does a Mac use" articles can say.

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