A dining room table can be any size. It is the measurements, however, that are most important for designing and then making a table that can be used. There are many different aspects to consider when planning a dining room table. You will need to decide the size of each place setting as well as how much room you want in the middle of the table. Also take into consideration how much room you want around the table and the dimensions of the room in which you plan to place it. Once you have sketched out the plan, you will be ready to add properly calculated measurements.

Draw a scale map of the room that will hold the dining table and chairs. This will help you to determine the space available and subsequently, the measurements of the table. Obviously, the room size is very important. Once you have determined the room size it will help you choose the length and width of the table and the amount of surrounding space. At that point you are ready to insert the table measurements into the room diagram to make sure the chosen dimension for the table fits the room.

Draw the room to scale on a piece of 8.5 by 11 paper. As an example, if the room is 20 feet by 15 feet, for our scale drawing one foot is equal to one inch. Reduce the measurements by half to make the room fit the paper. The resulting scaled room is now 10 inches by 7.5 inches. When inserting table dimensions to the scale drawing convert the feet to inches and divide the number by two.

Sketch out the shape of the dining room table. Many dining room tables are square or rectangular. It is much easier to calculate the dimensions for a four-sided table than it is for one that is round or has curves.

Determine how much room you want to allot for each person who will be sitting at the table. A minimum of 23 inches per person is recommended. This per person space refers to the amount of room needed from the left side of one person to that individual's right side. If you want to allow for some extra room, 30 inches per person works as well. Use the chosen measurement when determining the table dimensions.

Figure in the space needed across the table for each setting as well as the space needed in the middle of the table to accommodate dishes and food. This usually requires at least 12 inches of space. The width of the interior part of the table, that holds the dishes and centrepiece, can range from 30 inches to extra-large 44 inches. Therefore, with a place setting on each side the width of a rectangular table can range from 54 inches to 68 inches. For a square table this width would also be the length of the table. A table with only 30 inches for the dishes and centrepiece can be very cramped. This consideration may give way, however, to concern over the size of the room the table will be placed in. When choosing the width of the table, take into account the width of the room the table will go into and how much room you want on the centre of the table. Inserting this width into your room drawing can help you determine the appropriate size of the table. Using the scale from step 3, a 68 inch width is also 5.6 feet. Drawing the table to 5.6 feet scales down to a table that is 2.8 inches in width on paper. A 54-inch or 4.5-foot wide table scales down to 2.25 inches on paper.

Calculate the length of the table based on the number of place settings on each side as well as a place setting on each end. From step 3, the length of a place setting is 30 inches. The measurement for the place setting at the end adds on 12 inches because the orientation is different from settings on the sides of the table. If you have two place settings on each side and allow 30 inches per setting then the length of the table is 84 inches or 7 feet long. Again, this number will need to be adjusted, depending on the room measurements, particularly if the room is very small. See how the length matches up to your scale room. A 7-foot long table scales down to 3.5 inches on paper. This easily fits the length of our room.

Take into account the space needed for people to sit, walk around, and push back from the table. A comfortable space to push a chair back from the table is 36 inches, though when individuals push back the chair and cross their legs, 44 inches is more accommodating. If the table needs to be handicap accessible then 54 inches around the table is necessary. These measurements also need to take into account the space needed to walk around the table when people are seated at it.

Choose a height for the dining room table. A standard table is 30 inches high. Generally, 29 inches are provided by the table legs while the thickness of the table provides the additional inch. If you use a thicker table top then simply shorten the legs to compensate.

Plan the height of the dining room chairs to match the height of the table. A standard table is 30 inches off the ground, thus it will require chairs with seats 16 to 17 inches from the floor. If the table height is greater than 30 inches you will need to increase the seat height to match the table dimensions. Choose dimensions that you find comfortable for the chair back and seat. Standard seat measurements are 15.5 to 18 inches for seat width, 16 to 18 inches for depth and 18 to 20 inches from the chair seat to the top of the backrest. Typically, chairs found at the ends of the table have arm rests, while the other chairs do not.