How Long from mating to fertile egg?

Next egg after a successful mating will be fertile.
David

how long will a chicken continue to lay fertile eggs after that?  Just 1?

Unless your hen is broody, she will likely Not sit on the eggs for hatching...... But if she's broody, it will be about 21 days until a hatch.

Can lay fertile eggs up to 3 weeks after mating, even if the rooster removed.

3 weeks?  any instanced of being longer?

I was given some gray Jap eggs from a breeder at show. He claimed that the hen hadn't been bred for 3 months. 1 out of 3 eggs hatched. You won't have the same fertility that you would have if she was freshly bred though...

3 weeks is the most i have gotting fertile eggs, after the male was removed. have been told to  be safe wait 4 weeks after changing males.

I collected 7 eggs at day 18....   3 were fertile..   I cracked open the eggs and saw that 2 outta my 4 hens were still laying fertile eggs at day 23...  Yeap..  however the other two girls either werent bred before they came or  sperm didnt last as long with them..  but my two roos are form a RIR and a BR...     I had an EE fertile but didnt know it until I tossed and buff orp.. nothing..

It takes 25 hours for an egg to make its way through the chickens internal egg laying factory.  The egg can only be fertilized during the first 15 minutes of this process.  If a rooster mates with a hen on Monday about the time that Tuesday's egg has started its journey through the hens egg laying factory, Monday's egg will not be fertile.  Tuesday's egg will not be fertile.  Wednesday's egg will probably be fertile.  If the mating occurs early Monday and Tuesday's egg is laid late on Tuesday, it is possible Tuesday's egg will be fertile, depending on the time of mating and the time the egg starts its journey through the hen.

After a rooster mates with a hen, the hen will probably lay fertile eggs for 10 to 14 days, even if she does not mate with a rooster again.  Sometimes it is less and sometimes it is more, but the average is around 10 to 14 days.  3-1/2 weeks is the latest I have seen reported on this forum. 

A rooster does not necessarily mate with every hen in the flock every day.  Just because a rooster has been with your flock for a few days does not mean that all eggs are fertile.

I'd be pretty confident the eggs would be fertile from 3 to 14 days after a mating.  After that, I believe your chances of fertile eggs drop off.  I understand breeders usually wait three weeks after a certain rooster has been removed from the hen to be pretty certain he is not the father.