Create panel > Geometry button > Standard Primitives > Object Type rollout > Box button
Create menu > Standard Primitives > Box
Tab panels > Objects tab > Box Object
Tab panels > Modeling tab > Box Object
Box produces the simplest of the primitives. The only variation of Box is Cube. However, you can vary the scale and proportion to make many different kinds of rectangular objects, from large, flat panels and slabs to tall columns and small blocks.
Examples of boxes
Procedures
To create a box:
On the Object Type rollout, click Box.
In any viewport, drag to define a rectangular base, then release to set length and width.
Move the mouse up or down to define the height.
Click to set the finished height and create the box.
To create a box with a square base:
Hold down CTRL as you drag the base of the box. This keeps length and width the same. CTRL has no effect on height.
To create a cube:
On the Creation Method rollout, click Cube.
In any viewport, drag to define the size of the cube.
As you drag, a cube emerges with the pivot point at the center of its base.
Release to set the dimensions of all sides.
You can adjust parameters to vary the length of one or more sides of the finished cube.
Interface
Creation Method rollout
Cube: Forces length, width, and height to be equal. Creating a cube is a one-step operation. Starting at the center of the cube, drag in a viewport to set all three dimensions simultaneously. You can change a cube's individual dimensions in the Parameters rollout.
Box: Creates a standard box primitive from one corner to the diagonally opposite corner, with different settings for length, width, and height.
Keyboard Entry rollout
See Creating Primitives from the Keyboard.
Parameters rollout
The defaults produce a box with one segment on each side.
Length, Width, Height: Sets the length, width, and height of the Box object. These fields also act as readouts while you drag the sides of the box. Default=0,0,0.
Length, Width, Height Segments: Sets the number of divisions along each axis of the object. Can be set before or after creation. By default, each side of the box is a single segment. When you reset these values, the new values become the default during a session. Default=1,1,1.
Tip: Increase the Segments settings to give objects extra resolution for being affected by modifiers. For example, if you're going to bend a box on the Z axis, you might want to set its Height Segments parameter to 4 or more.
Generate Mapping Coordinates: Generates coordinates for applying mapped materials to the box. Default=off.
Note: If a visible viewport is set to a non-wireframe or non-bounding-box display, Generate Mapping Coordinates is on for all primitives to which you apply a material containing a map with Show Map In Viewport on.