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How to Check File Size on a Mac (Files and Folders)
Select the file in Finder and press Command-I. The Get Info window shows its size. For a folder, press Command-I and wait for the number to finish calculating, or open View Options with Command-J and turn on Calculate All Sizes.
How do I see a file size with Get Info?
Click the file, then press Command-I (or choose File > Get Info). The General section lists Size, in a friendly unit and in exact bytes. Select several files and press Option-Command-I to open one Inspector window that totals them as you change the selection.
Get Info is the right tool when you need the exact byte count, for example to check a file against an upload limit.
How do I see file sizes in Finder without opening anything?
- Switch to List view with Command-2.
- Right-click a column header and make sure Size is ticked.
- Click the Size header to sort the biggest files to the top.
- Choose View > Show Status Bar to see the item count and free space for the folder. Selecting files shows how many are selected.
Open the folder, press Command-J, and tick Calculate All Sizes. Now folders show a size in List view too, so you can see which subfolder is hogging space. It is slow on a huge folder, so turn it off again if Finder lags.
How do I check the size of a folder on a Mac?
Select the folder and press Command-I. A folder size is not stored anywhere, so Finder has to add up everything inside, and it may show “Calculating” for a moment. For your whole disk, open System Settings > General > Storage to see a category breakdown.
How do I check file size in Terminal?
ls -lh photo.jpg # human-readable size
stat -f%z photo.jpg # exact bytes
du -sh my-folder # total size of a folder
du -sk * | sort -n | tail # biggest items here, in KB
mdls -name kMDItemFSSize photo.jpgls -lh and du -sh are the two you will use most. du -sk * | sort -n | tail lists the largest items in the current folder, which is a quick way to find what is eating space.
Why do Finder and Terminal show different sizes?
Two reasons. First, units. Finder reports sizes in decimal units (1 MB is 1,000,000 bytes). Terminal’s -h flags use binary units (1 M is 1,048,576 bytes). Second, size versus size on disk: a file takes up whole blocks on the drive, so a tiny file still occupies space.
We measured both on generated test files:
| Item | Exact size | Terminal said | Why it differs |
|---|---|---|---|
| Folder of 5 JPEGs | 5,368,893 bytes | du -sh: 5.1M | Binary units: 5,368,893 / 1,048,576 is 5.1; in decimal it is 5.4 MB |
| One 1,040,309 byte JPEG | 1,040,309 bytes | ls -lh: 1.0M | Rounded in binary units; decimal is 1.0 MB |
| A 3-byte text file | 3 bytes | du -k: 4 | Occupies one 4 KB block on disk |
When an upload form says “max 10 MB”, assume decimal and check the byte count with stat -f%z. A file of 10,000,000 bytes is the safe ceiling.
What if the file is too big?
Once you know the size, shrink it by file type. The video guide, the PDF guide and image methods compared each give a route. Zipping will not help for media; see zip vs compress. For email, see compressing video for email.
When is Smol the wrong tool for this?
Checking a size is a job for Finder and Terminal. Smol does not replace them, and you should not buy anything for this. Get Info, List view and du -sh are enough.
Smol earns its $29 afterwards, when the number is too large and you have a pile of photos, PDFs, video or audio to shrink. Drop them in or right-click in Finder, and each is compressed on your Mac with nothing uploaded, as a copy next to the original by default. See pricing.
How we checked this
Ran ls, du, stat and mdls on generated fixtures on macOS 27.0.1 and compared the output with exact byte counts. Finder shortcuts are the standard documented ones. Facts last checked . We make Smol, so treat our claims about it with the same care as any vendor’s, and see our editorial policy.
Checking file size on a Mac: common questions
How do I see the size of a file on a Mac?
Click the file in Finder and press Command-I. Get Info shows the size in a readable unit and in exact bytes. In List view (Command-2), the Size column shows it for every file in the folder at once, and you can sort by it.
How do I see folder sizes in Finder?
Open the folder in List view, press Command-J, and tick Calculate All Sizes. Subfolders then show their totals in the Size column. For a single folder, select it and press Command-I. Finder needs a moment to add up everything inside a large folder.
What is the difference between size and size on disk?
Size is the number of bytes in the file. Size on disk is the space it occupies, rounded up to whole storage blocks. A 3-byte file measured as 4 KB on disk in our test. Many small files therefore use more disk than their sizes add up to.
Why does Finder show a different size than Terminal?
Finder uses decimal units, where 1 MB is 1,000,000 bytes. Terminal commands with the -h flag use binary units, where 1 M is 1,048,576 bytes. Our 5,368,893 byte folder showed as 5.1M in du and is 5.4 MB in decimal. The bytes are identical.
How do I check the size of many files at once?
Select them all in Finder and press Option-Command-I for a single Inspector window with the combined size. In Terminal, du -ch followed by the files prints each size and a total line at the end. List view sorted by Size also works for a folder.
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