How to figure percentage of on time delivery

[On the grind]

I am an excel rookie and need to display the percentage of on time delivery on a spread sheet. I have the if/then figured out. This figures out and displays if the delivery was "on time" or "late" and they are put in a cell. But what I also need at the end, or bottom of the spreadsheet is the percentages of "on time" or "late". It looks something like this:

Days to deliver.....On time or late?
10....................On time
15 ......................Late
10.....................On time
7 ......................On time
21 ........................Late
etc. ........................etc.

This spreadsheet has around 100 results, currently. How do I write a formula (that also looks nice) to tell me what percentage out of all deliveries was on time? Or late? Of course these values are all in cells, so lets just call the title row "1" and the columns "A" and "B". (I know this is going to come out sloppy, but it's supposed to be two columns).

So I want to take the amounts of "on times" - "lates" divided by the total instances (right?). How do I write this?

Also, this is a perpetual spreadsheet; I am going to continued adding more data. Can it be written so the formulas don't have to keep being written over and over for the new cells?

Any quick help would be appreciated. Thank you.

 

[On the grind]

Ooopps!

I should have done what you said in your last sentence. I put the formula in the column I wanted to perpetuate! (A).

I got it now, Thanks.

 

[daniels012]

OOps!
="Percentage of on time deliveries are COUNTIF(G:G,"on time")/COUNTA(F5:F14)*100 &"%"
It should be:
="Percentage of on time deliveries are COUNTIF(G:G,"on time")/COUNTA(F:F)*100 &"%"

I am sorry!
No problem. Glad to see you got it!
Michael

 

[On the grind]

Thanks....

 

[On the grind]

One other thing...

This is my current formula:

"&FIXED(COUNTIF(A:A, "on time")/COUNTIF(A:A,">a")*100,1,0)&"%"

What if I want the formula to not consider anything before A259, but everything thereafter?

Would it be A259:A instead of A:A?

Thanks for any help.....

Paul

 

[daniels012]

No,
You would have to do
A256:A65536

Michael