How to Measure and Make a Drawer for a Vanity

Select a drawer slide. Most vanity drawers use a standard side slide mechanism available at home improvement centers. It is important to buy slides at the beginning of the project because the slides partially determine how wide you must make your drawer. A key difference in slides is the amount of weight they are rated to carry. Most quality slides are rated in the 75- to 100-pound range. Determine how you will use your drawer and pick a slide accordingly.

Measure the width of your vanity's opening. Measure from one side of the vanity to the other side with a tape measure. Look at the directions that came with your drawer slides. The directions will indicate how much width the drawer slides will add to your drawer. In most cases, drawer slides will add a 1/2 inch. In this case, you would subtract 1/2 inch from the measurement you just took of your vanity opening. This will be the width that you will make the drawer.

Determine the depth of your drawer. Examine inside the vanity to see if there are any obstructions -- such as a sink -- that will interfere with how far back into the vanity your drawer can stretch. If there are none, you can measure from the front edge of the side of your vanity to the inside edge of the back of your vanity. Subtract 1/2 inch from the measurement to account for the rabbet joints you will use to join the corners. If there are obstructions, measure from the front edge of the side of your vanity to the point where the obstruction begins. Subtract 1/2 inch from the measurement to account for the joints.

Determine the height of your drawer. Measure the height of the opening in your vanity. Subtract 1/8 inch from the measurement to ensure that the drawer has proper clearance. If you are making the opening in the vanity, determine how tall you want the drawer to be based on how it will be used. Many vanity drawers are 3 to 5 inches tall.

Select your lumber. Most vanity drawers will have sides, front and a back constructed with 1/2 inch thick hardwood lumber. Birch or maple are suitable choices, and both are readily available at home improvement stores. The lumber should be free of curves or twists. Be sure to select lumber that has a width that equals the height of your drawer, or else you will need to use a table saw to rip the lumber to its proper width. All lumber to be used for the front, back and sides must be precisely the same width. Select a quality piece of 1/4 inch plywood that is at least 1 inch larger than the width and depth of your drawer measurements.

Cut the front and back pieces of the drawer. Using the measurements you took for the width -- being sure to have subtracted for the space taken by the drawer slides -- mark your back piece with a tape measure and a pencil. Cut precisely on the mark with a table saw. Use the back piece to mark the proper length of the front piece. This will help ensure that the two pieces are exactly equal in length, which is critical for the drawer to be square. Cut the piece on the table saw.

Cut the side pieces of the drawer. Using the measurements you took for the depth -- being sure to have subtracted a 1/2 inch for the rabbet joints -- mark one side piece with a tape measure and pencil. Cut precisely on the mark with a table saw. Mark the proper length of the remaining side piece with the side piece. Cut the side piece on the table saw.

Cut the rabbet joints. A rabbet is a notch made in a piece of wood that aids in joining two pieces of wood together. Take the drawer's front and back pieces. Make a mark 1/2 inch from the end of one of the pieces. Draw a line across the width of the board on the mark with a pencil and square. The distance from the end of the board to the line should be equal to the thickness of your side pieces. Equip your router with a straight cutting bit. Set the depth of the bit to remove all but 1/4 inch of the wood. In other words, on a 1/2-inch board, you want the router to remove a 1/4 inch of material and leave 1/4 inch of material. Remove the wood from the end of the board to the line with the router. It is important that you make a straight cut along the line in order for the drawer to be square. Repeat the process for the remaining three ends of the front and back pieces.

Cut a rabbet for the bottom of the drawer. Take the back piece of the drawer. Make a mark that is 1/4 inch up from the bottom edge of the piece. Draw a line on the mark across the length of the board with a pencil and square. With your router still set as before, remove the material from the edge of the board to the line. Repeat the process on the remaining front and side pieces.

Cut the plywood for the bottom of the drawer. Add 1/2 inch to the measurements that you used to cut the front, back and side pieces. The 1/2 inch accounts for the 1/4-inch rabbet you created on each piece to accept the bottom of the drawer. Cut the plywood to size on the table saw.

Assemble the drawer pieces. Place the front, back and sides pieces together. The side pieces should fit flush into the four corner rabbet joints. Place a tape measure on one corner of the drawer. Measure diagonally to the opposite corner. Repeat the process with the remaining two corners. The two diagonal measurements should be identical. This indicates a drawer that is in square. Once satisfied with the fit of the joints, remove the pieces. Apply a thin layer of wood glue to all edges of the corner joints. Apply a wood clamp across the length of the drawer. Apply a wood clamp across the width of the drawer. Consult your glue bottle for appropriate drying times.

Secure the bottom to the drawer. Place a thin layer of glue along the rabbet cut along the bottom edge of all the drawer pieces. Drop the plywood bottom piece into place. Apply at least four clamps while the glue dries.

Add small finish nails to further secure the corners and bottom. Hammer two small nails -- called brads -- into each corner joint. Hammer the nails through the side pieces so that the nails will be less visible. Hammer the brads about every two inches apart along the bottom edge of the plywood.

Prepare the drawer for installation. Attach the drawer slides per the instructions that came with the slides. A decorative faceplate can be added to the front of the drawer with glue and wood screws, if desired. If a faceplate is not added, the drawer will be flush with the outside edge of the vanity.