# Should formulas include units?

I recently submitted a paper that includes formulas related to building physics, such as

Q = K (t_b - t)


where Q is the daily heating load, K is the building's heat loss coefficient, and so on. All the quantities should be familiar to the reader.

A reviewer asks that I provide units for the quantities in this (and other) formulas. But this formula will remain true no matter which system of units I use.

Should formulas include units? If not, how can I tactfully rebut the reviewer's request?

• You're right, they shouldn't. You can referer them to quantity calculus. I can give you a few references, but now I don't have the time to write a proper answer. Jun 2, 2017 at 17:12
• @MassimoOrtolano is talking about Buckingham's \pi calculus. The unit system may need to be specified generally, because physical equations have different constants depending on the unit system (e.g. Maxwell's equation have different factors in SI and Gaussian systems), or cosmological equations set c=h/2\pi=1. So, it might be good practice to mention the unit system used for the particular set of equations. However, if you use SI units overall (or some other common unit system in your branch of engineering), it should not cost a lot to add a sentence. Jun 2, 2017 at 17:19