When selecting a new house furnace most calculators display results as BTUs (based on the square footage, number of levels, estimated temperature, etc). What’s interesting is that most new furnaces are spec’ed at MBH.
What is the difference or correlation?
BTU is how much heat is produced at one instant, BTU/hr is the amount of heat produced in an hour. MBH is 1000 BTU/hr. However, BTU is sometimes used as an equivalent to BTU/hr, so the conversion might work. Wikipedia has an article that might clear things up.
1 MBH = 1000 BTU/hr. Thousand BTUs per Hour (MBH).