Saturday, December 27, 2008

How to Heat Baby Milk?

Using baby formula?

Ever wondered, precisely, how much volume of boiling hot water combined with how much volume of chilled cold water, will mix to give you 37 Degrees Celcius of warm water/formula mixture ready for baby to drink?

Well, thanks to some high school maths here is the answer.

Make x = mLs of 100 degree water

make y = mLs of cold water

make z = final mixture volume then:

x + y = z (volumes)
100x + 4y = 37z (temperatures)

we know z = 200 mL bottle required for baby feed
so x + y = 200
y = 200 - x
100x + 4y = 7400
100x + 4(200-x) = 7400
100x + 800 - 4x = 7400
96x = 6600
x = 68.7 mLs of 100 degrees boiling water water
y = 131.3mLs of 4 degrees cold water

Combine these to get 200 mLs of warm water ready to drink. Add your powder and viola!

This is the first time that I have found a simultaneous equation to have a real life application.

I will also be calculating, if you have a
bottle of chilled breast milk, how long do you have to leave it resting inside a jug of hotwater, for it to warm to 37 Degrees. This is very complex, and actually requires a differential equation (computer model) to simulate it. ... coming soon!

For information on
formula doses for baby age view here:

Thanks Minty

Return to our Breastfeeding Blog