Under 10,000 BTUs

Heats spaces less than 500 sq. in.

10,000-19,999 BTUs

Heats spaces 500 to 1,000 sq. in.

20,000 - 29,999 BTUs

Heats spaces 1,000 to 1,500 sq. in.

30,000 - 39,999 BTUs

Heats spaces 1,500 to 2,000 sq. in.

40,000-49,999 BTUs

Heats spaces 2,000 to 2,500 sq. in.

Over 50,000 BTUs

Heats spaces 2,500+ sq. in.