# How to convert size, when i have MPix and resolution?



## raku (Mar 4, 2012)

Hello all, I have one question. I need to know how to convert the sizes this way:

Let's say, that I have a picture, with that resolution: 2870 x 2777 (7.97MPix).

How can I know what width and height (in pixels) it will have on 1 Mpix, or 2.5 MPix? Has somebody an idea?

Thanks in advance,

raku


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## Robin Usagani (Mar 4, 2012)

2870 X . 2777X = 1 e 6

Solve X

2870 X . 2777X = 2.5 e 6

Solve X


Then just use multiply 2870 by X


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## 480sparky (Mar 4, 2012)

Schwettylens said:


> 2870 X . 2777X = 1 e 6
> 
> Solve X
> 
> ...



I doubt it's that simple.  Image files contain more than just pixel data.

I tried the pixel count idea, and reduced a 91.2 kB image 50%.  The result was a 76.9 kB file.


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## Robin Usagani (Mar 4, 2012)

OP never mentioned about file size.  All OP said was Megapixel.  It would have been simpler if OP kept the crop ratio to 2:3.  You confused MPix (mega pixel i guess) to MB sparky.


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## The_Traveler (Mar 4, 2012)

the size of a file is dependent on the original dimensions in pixels and, if any, the amount of compression with which it is saved.
So you can save a file with greater compression and the filesize will be smaller even though the pixel dimension stays the same.


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## raku (Mar 4, 2012)

Guys, I need only the new size in pixels. I have the big size, as mentioned in first post. I have it's width x height and megapixels. I have also Megapixels of the "new" size, which I want to get the size (width x height). I don't care about the quality, cause I don't provide the photos : ). I have to only know the exact size. So, do you know the formula?


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## 480sparky (Mar 4, 2012)

1 MP image size = (1,000,000 / Original MP image size) * Original MP image size


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## raku (Mar 4, 2012)

@480sparky
IMO, it still says me nothing. How should I use it to achieve my goal?


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## 480sparky (Mar 4, 2012)

raku said:


> @480sparky
> IMO, it still says me nothing. How should I use it to achieve my goal?



You want a formula, and you get a formula.  Now you can't figure it out?

Replace the Original MP number you have and insert it into the forumula.  Then calculate for the result.


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## 480sparky (Mar 4, 2012)

Step by step instructions:

Multiply your Original image pixel dimension together (width by height).

Divide 1,000,000 by that number.

Multiply your Original image pixel dimensions by the result.


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