Rick, I converted an old 14" bandsaw to cut metal. I love it!
It is just basic math to figure out the speed. You need to know the speed of the motor, the pulley combinations, and the diameter of the drive wheel.
Say the motor is 1725, the pullies are 2" on the motor and 12" on the saw. That means the drive wheel is spinning at 287.5rpm. ( 12/2=6 1725/6=287.5) The 14" wheel driving the blade has a circumference of 44" (14x3.1416=43.98) At 288rpm (rounded) The wheel moves the blade 12672 inches per minute (44x288=12672), which is 1056 feet per minute (12672/12=1056)
As you can see by the example, even with a pretty big difference in the pulley size and a slow rpm motor the blade is still too fast for steel. The example would need a jackshaft or speed reduction of some sort to bring the rpm down by a factor of at least 10 to be usable.
On my saw I accomplished the slow rpm with an old speed reduction unit along with a small pulley on the gear reduction spinning a large pulley on the saw.
I felt it was worth the effort because I have a good 14" saw for wood and a large horizontal metal cutting bandsaw for cutoff. The ancient saw that I slowed down is great for cutting shapes in steel. I also use it for things I would have grabbed a hacksaw for, such as cutting off bolts or brass rods, etc. I use a 1/4" wide blade in it so that I can cut tight radius shapes.
I hope that the example I gave can help you with your project. If I explained it too poorly to make sense please don't hesitate to say so, so that I or someone else can clarify it.
Good luck and have fun.
Alden