1 unit/1500sf of lot area. 2,900 sf lot. Does 1.9 = 1 or 2 units?

[Rami W.]

Never had the opportunity to build, just yet, but I have always been curious.

If zoning states 1 unit allowed for every 1500sf of lot area and the lot just shy of the next full unit, lets say a 2900 sf lot, will the city still allow it for 2 units or does 1.9 mean you are only allowed 1 unit still?

Or are there other calculations/factors in play here, like difference afters setbacks are subtracted, how lenient the city planner is, etc.)?

Thank you!