Anchor chain sizing

[Peter]

Looking to purchase a new length, 80m, of calibrated anchor chain as going cruising this year. My question is are they any "simple" calculations out there to give me an indication on what size of chain, ie 10mm, or 12mm, which grade or loads imposed on a chain by weather/sea. Or any other method for sizing up a anchor chain, or just go with what I've got as it has not failed yet. Plus any other comments on buying anchor chain, ie who off, or who not to buy from, what questions to ask, is ebay any good etc. .
At the moment not worried on calibration as no windless yet. Current chain is 10mm for a 45ft, 13te (maybe up to 15te with all the stuff on board and not quite sure of unloaded weight) yacht.

Thanks

Peter

 

[TQA]

I have a similar size boat and use 10mm short link chain. 5 years living on the hook and so far so good.

 

[GHA]

One of the better sites here...
http://alain.fraysse.free.fr/sail/rode/rode.htm

And another..
http://www.awelina.co.uk/anchor_rode/rode_length.htm

 

[vyv_cox]

Most owners of boats of your size would be using 10 mm. There is a good deal of information about chain on my website at http://coxengineering.sharepoint.com/Pages/Chaindefinitions.aspx