I didn't include items that require things other than Wood (such as Bookshelves). Please let me know if I missed anything! Also, in case the headings aren't clear enough: Time is the burn time in seconds of an item, and Value is just Time divided by Cost. Mind that items in a furnace always take exactly 10 seconds to smelt.

In addition to this, could you edit your question to target one of the objective of the question: To clearly identify that the smallest division of wood (sticks) is infact worse off than planks.

Also, I suspect the Fence's cost might be wrong. Shouldnt it be 9?

@Rainbolt I can see that. However to facilitate easier reading, a final conclusion can be stated or perhaps tl;dr. Either way, It works for me. Just making a suggestion so i can arrow people that make the mistake to this answer.

@Rainbolt It could be perhaps due to me being used to writing reports. The conclusion of this table with regards to one of the objective which is planks vs sticks should be shown clearly.

@DarkDestry The sticks vs planks part wasn't in the original question. I'm adding more now about it :-)

@DarkDestry I've updated the answer to specifically answer your subquestion. You may be surprised (as I was!) to find that the answer actually changes a bit.

@Schism In fact I am, However, I suspect once again, that the values use may be wrong. The cost of Charcoal* In this case would be 33 and not 30 as it either take 2 sticks or 1 plank to cook. This would make it value less than a plank to make the first charcoal. Which in turn might mean that unless you intend to cook more than x items, its actually better to just not cook that charcoal. Where x might be 15 based on my rough calculations.

That said, there is actually surprisingly more into efficiency that i first imagined when I asked this question.

@DarkDestry The cost of Charcoal* is one Wood (24) and two sticks or 1 plank (6), giving 30.

@Schism Ah, I see now. Then could i ask why is Charcoal 27 and not 27.75? as 1/8 of 30 is 3.75 and 24+3.75 = 27.75

It does in fact come out to 24 3/7, meaning the value approaches exactly 7, rather than 7 1/9 as I had before.

(Incidentally I've cleaned up my comments on the answer; I suggest that you do the same for the relevant comments.)

c_n is the cost of the nth group of charcoals

so for example c_1 is 30 since we use planks/sticks

then, we can use that charcoal for the next 8 charcoals since it's more efficient than everything else

Oh ok i was confused at the syntax

Cuz normally i would see C under choose

ah yeah, I used c for cost but perhaps a or t or x would be better :P

Perhaps you need to clarify that C_n refers to the n^th time the charcoal has been cooked.

Bty also thanks for giving me the realisation that there sub script and superscript existed in the markup of the editor

I'm hesitant to add it in (I feel like I've bumped this post too much already!) though if I make another edit I definitely will.

And yeah, there's a list of permissible HTML here