Pool Volume Estimate with Pool Math

[Plefasu]

I think I am on the right track here but wanted to get a second opinion. I think I wildly overestimated the volume of my pool. It has a big baja step and is curvy. I recently did a drain and refill and added 440 lbs of salt thinking I would get the pool just under 3000ppm and add from there(20,000 gallon pool volume). When I got my salt test kit the salt tested at 4000ppm. This was my first indication I had something wrong. Then I ran my SWCG with 1.38 output at 50% for 12.75 hours and the FC went up by 3.5. Both of these numbers seem to indicate a pool more like 13-14000 gallons. Am I thinking correctly here?

 

[ajw22]

Yes, both those calculate to around 13,000 gallons.