WASHINGTON — D.C. homeowners thinking about selling should focus on their bathrooms.

The value of a two-bedroom row house that has just one bathroom increases by an average of $59,871 when a second bathroom is added.

Even a half bath adds, on average, $23,228, say the numbers from the D.C. Office of Tax and Revenue and D.C. Real Property Data.

The District’s Office of Revenue Analysis, in its “District, Measured” blog, analyzed market values for more than 15,000 two-bedroom single family homes to come up with the math.

On average, adding a half bath to a one-bathroom home increases its value by 6 percent, and adding a full bathroom increases the value by an average of 15 percent.

It also depends a lot on the neighborhood.

In Georgetown, the difference between a one bathroom and two bathroom property is almost 25 percent, or $75,000.