I am building a prop for my wife's dance recital. She wants a 25" diameter turntable to turn 25 RPM with a 110lb dancer standing o it. I will use 4 standard equally space caters from local hardware store to support the edge of turn table then use a gear motor as the pivot point. I need to know how much torque I would need t start this turntable and keep it turning. Thank you!

I don't know what a "cater" is, but assuming it's some sort of a bearing - to determine torque you need to figure out the friction of these bearings. You also need to specify how quickly you want the turntable to spin up to 25 RPM, and the weight of the 25" platform. Hint: if you say you dont care how long it takes to reach 25 RPM and if you say that the bearings are frictionless the answer is that you need 0 torque.

You need to re-think the speed of the platform. 25 RPM may have the person on the turntable barfing before long.

I assume you me "casters" instead of "caters".

What size motor do you plan to use and what type of gearing or belt drive are you planning to use?

How are you planning on driving the platform?