bike measurements and bike selection

There's websites that give you some data based upon your input, but it's not really useful... Body measurements is only part of the equation (and I'm not talking leg length, but rather lower leg length, upper length, etc.), you also need to add core strength, flexibility, types of races/riding, riding experience, distances you ride/race, current/previous injuries/issues... all this adds up to a unique fit for you. The online calculators to take body measurements in consideration (although not at detailed as actually needed), and scratch on the surface of core strength and flexibility, but completely ignores the rest.

In short, spend the money on a bike fit before buying a bike. You're better off with a less expensive bike that fits, than a more expensive that doesn't.... Keep in mind that the rider accounts for the vast majority of the aerodynamic drag.