This may or may not be useful to people out there but I wrote this as I was fed up watching a kettle boil - so to speak - as I could be getting on doing other things but wasn't sure how long it would take for my water to reach strike temperature. There are two versions in the spread sheet: Metric = Heating liters of water to temperatures in °C US = Heating quarts of water to temperatures in °F. In either sheet you can use a slider to select the power of your boiler and another to select the TARGET temperature you want to heat the WATER too. I am not clever enough to know how you would work it out for Wort - which will be different to that of pure water (by how much I am not sure but it wont be too far out). You can set the value of the target from 30°C to 100°C (86°F to 212°F). In the example shown below I have set it to strike water temperature - Time for a beer I think... The value in cell C4 can be changed to set the starting range of all the temperatures along the row. This is so you can make a quick look-up for the range of temperature you are likely to encounter with the water source you use. I have only used the range from 1 to 30 (liters or quarts) but you can extend it yourself if you feel the need. I have NOT locked down any of the cells so you alter the sheets at your own risk. I originally did this sheet so I could print it out and paste it on my brewhouse (garage) door. The spreadsheet is zipped so you will need to unzip it first before you can use it. Have fun.