It depends on what is your baby’s preference. My baby likes his milk slightly more on the warmer side so I use around 41-42 degrees water. Else you can use around normal body temperature like 37 or 38 degrees (mimics breast milk temperature).
Recommend to get a bottle warmer. It saves a lot of time and we don’t have to test the temperature before feeding. We just use cooled boiled water and heat up in the warmer. I’m currently using tommee tippee’s one.
You can read the instructions on the formula tin. It does mention the temperature to mix the powder.
i use 45 degree. there are those water dispensers that have 45degrees for milk.
lukewarm water.