Year five to 13 pupils around the country were taking part in the survey, hosted by the Department of Statistics and the University of Auckland.
At Columba College yesterday, out came rulers to measure the length of pupils' hair, tape measures to record the circumference of necks and scales to weigh school bags.
Next, pupils answered a range of questions including how they usually carried their school bags, through to the types of technology they used.
Information gathered would be available to schools for maths and statistics and to give an insight into teenagers' lives.
It was the fifth time the census had been held in New Zealand and it was also run in Australia, Canada, Ireland, Japan, Britain and the United States of America.
