Resize a Layer Using Free Transform
There are a couple of ways you can change the layer size in Photoshop, and both involve the Transform tool. There are options for freely adjusting the size up or down and inputting specific measurements to get it exactly the size you want. Here’s how to do it.
Free Transform
Resize a Layer to a Specific Dimension
If you don’t want to freehand transform layers but have some specific dimensions in mind, you can set its size to exactly that.
Resize a Layer Using Other Transform Tools
You can use several other transform tools, although these tools reshape the layer as much as they resize it. If you don’t want a linear increase in size for the layer, want to alter its perspective, or change its proportions, select Edit > Transform, then select one of the tools listed there (other than Free Transform). The tools do different things, so play around with them to see what kind of effects you can conjure.