# Storage of files onto a DVD-R or CD-R

Hi,

I'm trying to work out how many files of a certain size I could fit on a CD-R or a DVD-R.  The images are all scanned.  I found the following equation which helps estimate the size of a scanned document:

Resolution (X) x Resolution (Y) x Document Height(inches) x Document Width(inches) x Colour Depth

Therefore an A4 document scanned at 200DPI in b/w would be:

200x200x8.27x11.69x1

= 8700867 Bits

Which is 1087608Bytes or 1062Kb or 1.04Mb

Looking at this I estimate that I can get 675 files on a CD-R and 4,018,109 Files on a DVD-R.

Am I calculating the DVD-R storage incorrectly, the difference between and CD-R and a DVD-R seem astronomical?
Aaron

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Thanks Aaron,

I would be looking at using compression Group 2 or 3 so with a ration of 1/10 and 1/20 respectively I should be able to get a great deal more onto a CD or DVD.

For example, the 1.04Mb file compressed returns the following file sizes:
G2 : 106.21Kb
G3 : 53.11Kb

Thats 6,591 and 13,181 files onto a CD respectively.

My question now is, now that my files are in Kb what is the math/equation now to show this in relation to a DVD-R disc?  Do i need to first need to convert the Kb to Gb and if so, what is the equation?

Thanks again.
You are calculating the DVD-R size wrongly.  The CD calculation is pretty close.  I get 677

Also there are Mb, Gb and also Mib and Gib.

Your calculations are above are using MiB and GiB.  See http://en.wikipedia.org/wiki/Mebibyte

One is a multiple of 1000 and the other is a multiple of 1024.

Now for DVD size see http://en.wikipedia.org/wiki/DVD-R#Recordable_DVD_capacity_comparison and for CDR size see http://en.wikipedia.org/wiki/Compact_Disc#Disc_shapes_and_diameters from which we can see that a standard CD has a size of 650 or 700 MiB (737,280,000 bytes) data capacity.

Let's assume that a CD and CD-R have the same capacity.  Then

737,280,000 /  1087608 is approx 677.

For the DVD-R we'll use 4,707,319,808 (see Wikipedia link)

4,707,319,808 / 1087608 is approx 4328
SOLUTION

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I think the easiest way to look at it is whatever you see on the CD you will have about 6.7 times more space on the DVD. As Dbrunton did the math for you on this and came up with (4328 which was close to the 4500 I got) depending on just how accurate you want to be. However I think 6.7x shows a good comparison and there will always be some variance in file size /indexing etc.
By the way anthony Cudos for using astronomical in your question I think that is a sorely underused word ha ha.