The term "upright piano" refers to a particular type of instrument -- the tallest type of vertical piano, at least 47 inches high and sometimes as tall as 60 inches. People today often use the term to refer to any sort of piano that isn't a grand; these come in a range of sizes and are called "vertical pianos."
Vertical pianos all have similar lengths and widths, so the main difference between the models is the height. Although the dimensions vary slightly from instrument to instrument, most vertical pianos are about 5 feet wide and 2 to 2 1/2 feet deep. Allot a 5-foot-by-5-foot floor space for a vertical piano and its bench.
The smallest vertical pianos, spinets are 36 to 40 inches tall. Although they fit in tighter spaces than other pianos, they lack the richness of sound of larger models because of their short strings.
Console pianos range from 40 to 44 inches tall. They originally were designed to be decorative as well as functional, so they tend to come in a wider range of aesthetic styles than other models. Their sounds are slightly richer than that of spinets, particularly on the bass notes.
The most common choice for schools, churches and modern homes, a studio piano is 44 to 47 inches tall and has a sound similar to that of a standard grand piano. Aesthetically, studio pianos tend to look simple and sturdy.
The largest type of vertical piano still being made is the professional piano, which can be 47 to 52 inches tall. Its sound is almost as good as that of a large grand piano. Like studios, professional pianos generally are plain and functional in appearance.
Upright piano height overlaps with that of professional pianos, starting at 47 inches, but the term most often applies to antique pianos 55 inches or taller. Modern manufacturers don't usually make models taller than 52 inches, but vintage uprights from the early 1900s through the 1940s can be as tall as 60 inches and feature more elegant craftsmanship than any other type of vertical piano. If they have been well cared for, they can have a richness of tone to match.