dilution water change formula

[Acroporaaddict]

Is there a formula for dilution from water changes?

for example:

50g of 8.5 dkh change 10g of water with 7dkh water. New tank dkh is?

or
50g of 480 Ca change 10g of water with 420 Ca. New tank Ca is?

I'm not necessarily looking for answers, more so the formula for my knowledge and future reference.

Thanks

 

[Flippers4pups]

@Randy Holmes-Farley may know.

 

[Philipgonzales3]

Would this help any?
https://www.hamzasreef.com/Contents/Calculators/EffectOfWaterChanges.php

There's more calculators here as well.

https://www.hamzasreef.com/Contents/Calculators/

 

[Acroporaaddict]

The first one is what I was looking for. Guess I don't need the formula if I have a calculator. Thanks