I need help please with a odometer calculation
 

I changed tire size, and I simply need to know the distance I travel with the new tire. The old tire was 27.4" in diameter and the new is 24.2" If someone could tell me the easiest way to convert the odometer reading. I would be most grateful.

Your new odometer and speedometer reading will be 113% of your actual speed. Meaning, you can take the current speed you are traveling and multiply it by 0.88 and you will receive your actual speed.

27.4/24.2=1.13 24.2/27.4=0.88

thanks very much,

This site is great to figure it out as well: Tire Size Calculator