Stop valve sizes for whirlpool tub and faucets

Hey guys, I have 1/2 supply lines running in the masterbath, which stop valve size should I use for connecting to a whirlpool filler faucet? 1/2" inlet to 1/2" outlet, or 1/2" inlet to 3/8" outlet? same question for connecting to a sink faucet?

I think that 1/2" to 3/8" for a toilet stop valve is normal but don't know the same for whirlpool and sink faucets.

BTW, would stopping down the line at the valve from 1/2" to 3/8" will increase the presure at the faucet/showerhead?

thanks much!

valves

Why would you want any valves there? They would normally not be accessible. Reducing the size will increase the residual dynamic pressure INSIDE the valve, but reduce the pressure and volume at the tub. In other words if you used it as a squirt gun, it would shoot farther, but with a lot less water flow.

If you have access then I'd add the stops just in case you ever have to service the faucet valves. The only whirlpool tub I've installed had 1/2" pipe threads so I just put in a ball valve below and plumbed right to the faucet. As for the shower... I'd try to keep it 1/2" all the way. 3/8 will not give you the volume you need unless you have a water saver type head which pretty much reduces the volume anyway.

thanks guys for the quick replies! much appreciated!

thinking about it, I will probably will not put stops on the tub faucet, as they will not be accessible as stated (will save me some bucks too )