In Sri Lanka, the perch is a widely used unit of measurement, particularly for land area. It is part of the old British imperial system and remains common in real estate and land transactions in the country.
1 perch = 25 square meters or 272.25 square feet.
Additionally:
•40 perches = 1 rood
•160 perches = 1 acre
This system coexists with the metric system, which is officially adopted in Sri Lanka, but many people still use perches informally when dealing with property.