Calvert County’s schools chief is leaving the Southern Maryland school system of 16,000 students in early August, officials announced Wednesday.

Superintendent Jack R. Smith, 55, will step down after seven years in the top job and nearly a year before the end of his second four-year contract, officials said. His departure culminates a 14-year career in Calvert, including three years as deputy superintendent.

In a letter to the school community, Smith talked about spending time with a new grandson and “some potential opportunities . . . that look intriguing.”

Smith declined in an interview Wednesday to detail job possibilities, but he said the decision comes after a year of “personal events that have caused me to reflect.” Being superintendent was all-consuming, seven days a week.

“A great job,” he said. “I have loved this work.”

Still, Smith said it was time for a change.

The county’s school board plans to appoint an interim superintendent soon, probably from within the school system, said Calvert County Board of Education President Eugene M. Karol. The school board expects to conduct a national search for Smith’s replacement, he said.

“It’ll be a loss to have him go — and he’s done a good job here — but superintendents do move from place to place,” Karol said.

Board member Joe Chenelly said Smith — who earns $169,000 a year — had asked for a contract change in May that paved the way for his early departure. He informed the board of his decision last week.

Calvert school leaders credited Smith with leadership in improving state models for teacher and principal evaluation and with significantly increasing the number of Calvert students involved in Advanced Placement courses and other rigorous programs.

They also cited as accomplishments his efforts to modernize career and technology education programs and create new science, technology, engineering and math programs.

Smith said he was proud that more students were choosing challenging programs, whether they were college-bound or preparing for fields such as cosmetology or welding.

“Every kid needs to go through the school system and leave with some options and choices,” Smith said.

Smith said his decision was unrelated to a recent incident that drew widespread attention: the suspension of a 5-year-old boy who brought a cowboy-style cap gun onto his school bus because he wanted to show the toy to a friend.

The child was suspended for 10 days, a punishment later reduced to three days. Last week, school officials declined a request to clear the incident from the child’s school records. The family is appealing that ruling to the school board.