How to read the logical and physical file size using C# api. <img src="https://i.stack.imgur.com/RgH6v.png" alt="enter image description here">

<pre class="prettyprint"><code>(new FileInfo(path).Length) </code></pre> is the actual size. As for size on disk, I don't think there's an API to get it, but you can get it using the actual size, and the cluster size. There's some info on the calculation required here: http://social.msdn.microsoft.com/Forums/en-US/Vsexpressvcs/thread/85bf76ac-a254-41d4-a3d7-e7803c8d9bc3

How to check logical and physical file size on disk using C# file API

1 Answers

(new FileInfo(path).Length)

is the actual size. As for size on disk, I don't think there's an API to get it, but you can get it using the actual size, and the cluster size.

There's some info on the calculation required here: http://social.msdn.microsoft.com/Forums/en-US/Vsexpressvcs/thread/85bf76ac-a254-41d4-a3d7-e7803c8d9bc3