There must be thousands and thousands, because you can measure almost anything! There’s even a measurement scale for how hot chillis are called the Scoville scale. There’s a standard set of units called the International System of Units which most people in most countries use. These measurements are things like metres, kilograms and seconds which most countries use – although UK and USA still have some measurements in old units like stones, pounds and feet/yards.
I agree with Alex, I think there are almost infite units of measurements. Also, because as long as record what system you are using, you can make anything a unit of measurement. I could say that I am 164cm tall, 5’4″ tall, or approximately 8 bananas tall. 😀 Wow, eight bananas doesn’t sound very much… but the average banana is about 8 inches or about 20 cm long, so… it must be right!