Stability is the most important factor to establish first when sizing your metal table base. Before you get any further in the sizing process, it is most important to determine the bare minimum the for the width of the base. The “golden rule” is to have the width of the base at the floor be at least 0.6x the overall height of the table. This works out:
Dining Height (30″) – 18″ Minimum Width
Counter Height (36″) – 22″ Minimum Width
Bar Height (42″) – 26″ Minimum Width
Keep in mind these are the bare minimum recommendations. “Stability” can be a subjective term, so it can be beneficial to increase the width from these minimums for some extra “insurance” against instability issues. It is important to note that these minimums are for the base width at the floor. All of our products are measured at the widest points of the base (not including mounting plates). So with some of the designs that taper in at the bottom, it is critical that the base is sized wide enough at the top so that the bottom portion is still within the stable range. Common bases that taper in at the bottom are as follows:
6″ to 10″ should be added to the minimum width for stability to these bases depending on the height.
This part can get a little tricky, as there are many different types of tabletops that all have different support requirements. In general, it always best to check with the top fabricator as to what they recommend for the base size. Most types of top materials are rated for how much overhang is allowed off the edge of the base, but some materials also have requirements for the “max amount of unsupported length” throughout the length and width of the top. Again, it is best to check with the top fabricator on what size base is recommended, but here are the general, “industry standards” for overhang allowance:
Glass – 12″ of overhang
Stone – 14″ of overhang
Wood – Varies, but generally 15″ to 30″ of overhang is fine
For stone tops, you can increase the amount of overhang from the edge of the base to the edge of the top by adding a plywood support in between the base and the stone.
Steps #1 and #2 above will help you determine the minimum size your base should be. As mentioned previously, it is beneficial to have a base larger than these minimums in order to provide a little extra insurance for stability and support, however you don’t want your base to be too large as to impede with leg room while sitting at the table, or chair room while sliding the chairs under the table. In general, here are the considerations to keep in mind for leg and chair room:
Leg room – 10″ of overhang is considered comfortable when sitting at the table for leg room
Chair room – 14″ of overhang is considered adequate to almost fully slide your chairs under while not in use
Keep in mind most of our base designs allow overlap, or have the metal base supports land in areas where the chairs can be positioned around so as to not cause any interference. For example the Criss Cross base has the metal tubing running at steep angles, which allows for several inches of overlap when sliding in your chairs right where the base is.
The above 3 steps will hopefully guide you to come up with a base size that you feel confident is appropriate for your application. It is important to note however that these are general, “rule of thumb” guidelines, and do not always apply to every application. For example entryway and sofa tables are often 30″ to 36″ tall, but average only 14″ in width. This is way outside of the stable range, but with them being up against a wall or sofa, that helps stabilize them.
If you go through the above 3 steps, and the recommended size for your metal table base does not meet the rest of your requirements, it would be best for you to contact us to see what your options are. Sometimes we can recommend a specific base design that will allow overlap, or we can come up with a custom solution to meet your requirements.
This doesn’t typically affect the legroom or the stability of the table, but it can affect the “rigidity” of table if the tubing size is grossly undersized for the intended application. It is also an important factor for both aesthetics and support for the tabletop. Too small of a material size will look dwarfed by the top, and may look awkward. Too large of a material size may look too bulky for the application and will increase the cost of the base unnecessarily. Different bases are made from different material shapes, such as square tubing, rectangular tubing, or flat bar. Below lists how we typically come up with a recommendation for tubing size for a given application:
1” square – Only recommended for small tables, such as end tables, or coffee tables with lightweight tops.
1-1/2” square or 1×2 rectangular tubing – Smaller, lightweight applications. Can be suitable for bench applications depending on the base design/style
2” square– minimum size recommended for dining applications. Suitable for most sizes and medium weight applications
1×3 Rectangular – Suitable for smaller dining applications. Material can flex under heavier or larger tables, so it is not recommended for larger dining tables, counter height, or bar height applications.
3” square or 2×3 rectangular – Recommended size for larger bases or for applications with heavier tops. Suitable for almost all size and weight applications.
4” square or 2×4 rectangular – Will provide a “massive” look to the base. Not recommended for smaller applications as the larger material will cause the base to lose its shape. This is the recommended material size for extremely large and/or heavy tabletops as it will look the most proportionate and best support the weight.
1/2″ thick glass top, 40″ W x 84″ L, dining height – The minimum base size we would recommend for this top would be 18″ W (from #1, stability) x 60″ L (12″ of overhang on both ends). This would allow for the most amount of leg and chair room while minimally meeting the other requirements. A base size of 26″ W x 66″ L would be a more conservative recommendation.
3CM thick stone top, 60″ W x 120″ L, dining height – The minimum base size in this instance would be set by step #2, regarding adequate support for the stone, in both the length and width, which would put the base size at 32″ W x 92″ L. However if a plywood underlayment was used, we could safely drop the base size down to 28″ W x 84″ L to allow for more chair room around the base.
1-1/2″ thick wood top, 36″ W x 72″ L, bar height – For the width, the minimum would be set by the stability requirements, which would be 26″ W. The length of the base could be as little as 42″. We would likely recommend 28″ W x 54″ L for this application to give some extra stability insurance.
1/2″ thick glass top, 60″ round, dining height – Considering adequate support for the top, the base width should be at least 36″ so as to not exceed 12″ of overhang
3CM stone top, 48″ square, counter height – Square tops are often confusing to measure properly, since the size of the square is measured from the width of the flats, however most of our bases are measured from “corner-to-corner”. To size the base according to the same measurement scale the top is measured from, we use the Pythagorean Theorem to determine the size square of the base, using A² + B² = C². At counter height, the base should be at least 22″ W. Giving a little extra security, we would recommend a 24″ base, so the base would need to have a 24″ box footprint. This works out to a base width of 32″ (see picture to the side for reference).
1-1/2″ thick wood top, 36″ W x 72″ L oval top – Oval tops can be one of the trickiest shapes to size properly. We recommend contacting us with your top dimensions and base preference so we can draw the base with the top to scale and determine the proper size.
3″ thick wood, 48″ W x 108″ L, dining height – With the massive wood top, adequate support to the top is most likely of no concern. The base could be as little as 18″ W x 68″ L and function perfectly. However we would typically recommend going a little wider to prevent someone leaning heavily on one side and possibly tipping the table over, so 24″ W x 72″ L would be our conservative recommendation to maximize leg and chair room.