A surge in passengers on Sydney's inner-west light rail line over the past year has prompted the operator to put on up to 90 extra services a week to cope with demand during peak travel periods.

The number of passengers using the trams rose almost 60 per cent to 6.1 million last financial year due in large part to the opening of a 5.6-kilometre extension of the line to Dulwich Hill in early 2014, government figures show. The line runs from Central Station to the inner west via Pyrmont, Glebe and Lilyfield.

The patronage statistics will not be a surprise to commuters who are increasingly finding carriages packed.

Most of the extra peak-hour services will begin from Monday, while the remainder will be put on by the middle of the year. In total, tram services will rise from 197 to 215 on weekdays.