Scale a layer

As with other transformations, scaling occurs around the layer’s anchor point. You can scale a layer beyond the composition frame.

To scale a layer proportionally in the Composition panel, Shift-drag any layer handle.
To scale a layer freely in the Composition panel, drag a corner layer handle.
To scale one dimension only in the Composition panel, drag a side layer handle.
To increase or decrease Scale for a selected layer by 1%, hold down Alt (Windows) or Option (Mac OS) as you press + or – on the numeric keypad.
To increase or decrease Scale for selected layers by 10%, hold down Alt+Shift (Windows) or Option+Shift (Mac OS) as you press + or – on the numeric keypad.
To scale and center selected layers to fit in the composition frame, choose Layer > Transform > Fit To Comp.
To scale and center selected layers to fit the width or height of the composition frame, while preserving the layer’s aspect ratio, choose Layer > Transform > Fit To Comp Width, or Layer > Transform > Fit To Comp Height.
To scale a layer proportionally in the Timeline panel, select the layer, press S to display the Scale property, click the Constrain Proportions icon to the left of the Scale values, and enter a new value for the x, y, or z scale.
To activate the Constrain Proportions icon and match the height to the width, Alt-click (Windows) or Option-click (Mac OS) it.

AfterEffects