It's up to 500 cals on a DD for the first two weeks. If you find you are stalling, then it would be worth dropping down to the 20% figure on the calculator (383 cals in your case) but if you are losing weight on 500 then that's fine. The UD calories are only on the calculator to work out your DD calories; you don't have to count on an up day, you just eat until you are satisfied but not stuffed.
Good luck x