中文：

套户比是指每套房屋的建筑面积与每户平均建筑面积的比值，通常用来衡量一个住宅小区的户型分布情况。

套户比的计算公式为：套户比 = 每套房屋的建筑面积 / 每户平均建筑面积。这个比值越接近1，说明小区的户型分布越均匀，每种户型的数量也越接近；反之，如果比值远大于或小于1，则说明小区的户型分布不均匀，某种户型的数量可能过多或过少。

套户比对于购房者来说具有重要的意义。了解一个住宅小区的套户比可以帮助购房者更好地了解该小区的户型分布情况，从而更好地选择适合自己的房源。同时，套户比也是衡量一个住宅小区规划设计是否合理的重要指标之一。

英文：

The ratio of housing units refers to the ratio of the building area of each housing unit to the average building area per household, which is usually used to measure the distribution of household types in a residential community.

The calculation formula of the ratio of housing units is: the ratio of housing units = the building area of each housing unit / the average building area per household. The closer this ratio is to 1, the more uniform the distribution of household types in the community, and the more similar the number of each type of household. Conversely, if the ratio is much greater than or less than 1, it means that the distribution of household types in the community is not uniform, and the number of some household types may be too high or too low.

The ratio of housing units is of great significance to home buyers. Understanding the ratio of housing units in a residential community can help home buyers better understand the distribution of household types in the community, so as to better choose a suitable property. At the same time, it is also one of the important indicators to measure whether the planning and design of a residential community is reasonable.