Not sure wat size of speakers I need

[shadowfox]

I have been looking around for speakers for my truck and I checked crutchfield and it said i need 6 1/2 for all for 4 speakers. But when i looked up speakers on best buy and amazon, they both said i need 5 1/4. Which one should i believe?

 

[RangerFabWorks]

crutchfield is the most accurate. im pretty sure it is 6 1/2 all around

 

[Lancaster]

I agree with blackwidow, crutchfield is most accurate. But, if it comes down to it, take the speakers out and measure them yourself.