Sales at Chipotle, the restaurant chain that is fast becoming the eat-outing brand that symbolises the tastes of the millennial generation, broke the $1bn (£67m) barrier for the first time in a single quarter in the three months to the end of March.

Sales in its stores open at least one year were up 10.4% in the quarter, whilst overall sales were up 20.4% to $1.09bn, compared with $904.2m in the same period last year. Profits increased 47.6% to $122.6m.

Steve Ells, Chipotle’s co-chief executive, said: “We are very proud of our start to 2015, as our average sales volumes reached a record $2.5m per restaurant.”

“I am pleased with our performance during the first quarter. 2014 was an extraordinary year for our business and we are off to a strong start in 2015. These results are particularly strong considering that we were up against 13.4% same store sales growth in Q1 last year and faced with harsh winter conditions in much of the country, including many important Chipotle markets.”

The company continued to increase its average transactions throughout the day, including its peak lunch and peak dinner hours. During the quarter, it increased average transactions by 21% across the entire day.

It said it was “well on track” to meet its initial guidance to open 190 to 205 new restaurants during this year. During the quarter, it opened 49 new restaurants, including one new ShopHouse, bringing its total number of restaurants to 1,831 including 10 ShopHouses in two Pizzeria Locales.

It anticipates entering new markets for both ShopHouse and Pizzeria Locale this year. The company previously announced plans to introduce Pizzeria Locale in Kansas City and also expects to open in a third market, Cincinnati later this year.