Scaling changes the size of an object.
The Scale transform button is a flyout that provides three types of scale. The type of scale visible on the main toolbar is the type that appears in the quad menu, accessed by right-clicking a selected object.
To scale an object:
Set the Select and Scale button to the scale type you want to use, then click it. The button highlights.
You can now select objects, scale previously selected objects, or both select and scale objects in a single mouse action.
Uniform scale does not change an object's proportions.
Use Uniform Scale to scale the selection equally along all three axes.
The center of the scale is determined by the Transform Center button. The axis constraint buttons and the Transform Coordinate system have no effect on uniform scaling. See topics later in this section.
Non-uniform scale can change proportions by having different values for different axes.
Use Non-Uniform Scale to scale the selection differently along the three axes.
The Axis Constraint buttons determine the axis or axes along which the scaling occurs. The Transform Coordinate system determines the direction of the scaling, and the Transform Center button determines the center from and to which the scaling takes place.
Squash scales two axes in opposite directions, maintaining the object's original volume
Use Squash to scale the selection in one direction along one axis and in the opposite direction along the other axes. Squash gives the appearance of maintaining the volume of the selection.
The Axis Constraint buttons specify the axis of scale, while the remaining axes scale in the opposite direction. If you use a double-axis constraint, the single remaining axis scales in the opposite direction.
If you scale an object and later check its base parameters in the Modify panel, you see the dimensions of the object before it was scaled. The base object exists independently of the scaled object that is visible in your scene.
You can use a tape measure helper object to measure the current dimensions of an object that has been scaled or changed by a modifier. See Precision and Drawing Aids.