You need to be logged into your SkyMiles account. If you are, you should see how many redeemable miles (SkyMiles), MQMs, and MQDs you'll earn at the bottom of the page when you get to Express Checkout. If you want to compare between different routings, you'll need to do that yourself. You can either select the flights to get to the Express Checkout page with different options or you can use a site like gcmap.com to determine how many miles each routing will cover which corresponds to MQMs (before any fare class bonuses).