This is a neat little program that you can download for free from www.pipeflow.com. (Or click on the image to go the PipeFlow website.) They have a number of hydraulic analysis programs, all of which I use, for sale at their website but this unit conversion program is provided for free, absolutely no strings attached. A screen shot of the program is shown below. In the example I’ve entered a flow rate of 3,000 gallons per minute and I’ve converted it to metric units. The converted flow is 11.36 cubic meters of water per minute.