The standard dining room chair, no matter its style or its composition, requires the same seating height. Measuring from the floor to the bottom of the table top, the height ranges from 28 inches to 30 inches high, with 29 inches as the average. A dining chair needs to allow enough room for the diners' legs to fit under the table. For this reason, the seat height is between 18 inches and 20 inches high, with 19 being the average.
There was a time when you would see stools only in one type of place -- in front of a bar. Most people selected stools for their kitchen snack bar or the bar in the family room. Things have changed. Not too long ago, the counter height dining or pub table was introduced as a more casual option for the dining area. At a height of 36 inches, comfortable seating would require stools with a seat height of 24 or 26 inches.
Most kitchen snack bars or islands stand at 36 inches high and call for stools with the same 24 to 26-inch high seats. If it opens onto your dining area where you might have a pub table, you would be able to interchange your stools to accommodate extra guests at either place.
Generally, bars stand 42 inches high and need stools that have a seat height of 30 inches. You might also find some pub tables at this height, so measure the height from floor to the bottom of the bar surface to calculate what height stool you'll need.
These measurements are based on normal-sized adults sitting on wood or lightly upholstered seats. If you're looking at chairs or stools with poufy upholstery, take into account the extra space under the table bottom that will be required for comfort and maneuverability.