Is there a 'calculator' online to determine when mine and my sister's eggs will hatch?

Ok, so me and my sister got 2 fertile chicken eggs a little over a week ago and we have them in an incubator with a temp. of about 100-102 degrees and VERY humid!! I was wondering if there is a "egg hatching calculator" or even "egg hatching estimator" online to determine when exactly our eggs will hatch, they are both healthy we just need to know around when they will hatch so we can have EVERYTHING ready for the big event!!! Thanks!!