Hatch Rate

[aart]

we just had four babies hatch out of 13. We had 9 eggs who didn't hatch, a few were fully developed, some not to much. This was my first time hatching and I feel so sad not all made it. What's been everyone's else's success rate for first timers? Did I screw up big time with these number?

The term 'hatch rate' can be hard to define.
Say you had 13 eggs.
4 were infertile and never developed at all.
2 developed but quit at day 10.
2 were fully developed but did not hatch.
1 hatched but died due to an open abdomen.
4 hatched and are thriving.
Which numbers do you use to come up with a 'hatch rate' percentage?
That may not be what you were asking, but came to mind when I saw 'hatch rate'.

Hatching can be tricky, it's part science/equipment, part 'art'.
It takes a lot of attention, and some experience to keep things adjusted,
and know when not to adjust things
It can be heartbreaking and thrilling.
Using number hatched divided by number set,
I've had 100% hatches and 20% hatches.

Calibrating your thermometers and hygrometers is essential.
Inaccurate thermometers is probably the most common reason for 'bad' hatches.
Here's how I test mine:
https://www.backyardchickens.com/ar...incubator-thermometers-and-hygrometers.73634/