Noah Okafor's first-half goal gave the hosts the lead at Elland Road, but Mathys Tel and Mohammed Kudus scored for Spurs to turn the game around.
Calvert-Lewin acknowledged that the team's hard work wasn't enough to secure a better result, but highlighted the positives from the game.
"It's frustrating, given the effort we put in to get ourselves in a good position," he said. "I think Spurs scored against the run of play, and then we worked hard."
He noted that there were chances created by the team that could have been converted, and that the Premier League is a competitive league where mistakes are punished.
Calvert-Lewin emphasized that he expects himself to put away chances when given the opportunity, and that the team's focus is on continuing the momentum built so far.
He also expressed confidence in the team's ability to compete with established Premier League sides, citing their recent displays against Tottenham and Newcastle.
Calvert-Lewin stressed the importance of staying balanced and focused throughout the season, with 31 games remaining and 31 chances to earn three points.
The result leaves Leeds with eight points from seven matches heading into the international break.