Sitting too low at a table or bar is uncomfortable and awkward. Since you cannot change the bar height, you'll have to change the bar stool height with either purchased or homemade furniture leg extender pieces. The same applies to smaller stools like footstools. In fact, you can extend the height of any piece of furniture with leg extenders.
Purchased Furniture Leg Extenders
Assemble the chair leg extenders according to the package directions, if necessary. For example, the tubes that fit around the leg may have to be snapped or screwed onto the part that sits below the stool leg and raises the height.
Insert the same number of spacer pieces inside each leg extender if your model of extender has this option. Some extenders have pieces that can be inserted into the leg tubes on top of the base piece to raise the height of the leg even higher than the base piece. Each of these spacer pieces raise the height incrementally.
Fit a leg extender on the bottom of each leg of the stool. Make sure the legs seat properly. Many types of extenders are designed for the legs of the stool to simply sit inside them and will fall off if you lift the stool. Some extenders have a locking mechanism that keeps the extender piece on the legs when the stool is moved. If yours has this feature, install them so they lock on. Each model of extender will fit onto the stool leg in a different manner. Follow the package directions.
DIY Furniture Leg Extenders
Decide how high you want your stool seat to be. Measure from the bottom edge of the crossbars of the stool's legs to the height you want the seat of the stool to be. The crossbars will rest on top of the extenders to raise the stool. Therefore, this method will not work if your stool has no crossbars or the crossbars are high on the legs. In this case you must purchase commercial furniture leg extenders.
Measure the distance from the floor to the bottom edge of the crossbars. Now measure from the floor to the seat of the stool. Subtract this measurement from the desired height. Add this difference to the distance from the floor to the bottom edge of the crossbars. This is how long your PVC pipe extenders will be.
Cut a PVC pipe with a hacksaw to the measurement you have from Step 2 for each leg of the stool. The diameter of the pipe must be large enough so a leg of the stool fits inside. Cut the pipe ends so that the stool sits level. For example, if the legs are straight, cut the ends level. If the legs angle outward, cut the pipes at an angle. This angle depends on your stool's design. In addition, you can add end caps to the pipe pieces that will rest on the floor to prevent chipping or breakage.
Fit a cut pipe on the bottom of each leg of the stool and push it to the crossbars. This type of leg extender will not stay on the stool's legs if you lift it. In addition, if the PVC pipe is much larger than the stool legs, the stool will be wobbly. Therefore, choose the PVC pipe accordingly.