When you mix ammonia with water, you need to give it pretty much time to mix thoroughly. Usually you shouldn't test for 20 or 30 minutes, especially if you are still establishing what the right amount of ammonia is for you.
When you perform the API tests, its important to follow the instructions to the letter. I use a little kitchen timer that hangs around my neck, so that I can do other things but then check the colors at the right time. I always use the same bright light and hold the tube and color chart the same distance from that light.
Don't be surprised if the calculator doesn't give you what you expect. Its the test results that you must go by.
~~waterdrop~~