With update 2.0.2, the devs added a feature that lets you see how much you will gain from each level of a contract both in silver planes and XP
Here’s how you do it
Step 1 - select an airplane card and click on the contract admin button (circled)
Step 2, Use the arrow top right to flip the card around
Step 3: Click on the rewards tab botttom right of the card
Step 4: Click on the upgrade button that shows up
Step 5, here’s the full list for you to see