# Photo Ratio Calculator

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What are the maximum image dimensions that can fit in X megapixels? How big can we print it?

1. Photo Crop Ratio Calculator

What image size do we get if we buy a 50 megapixel camera? Or in any 50 megapixel image?  It depends on the aspect ratio.

The calculator below shows your request and also automatically adds results for a few standard aspect ratios (1:1, 4:3, 3:2, 16:9). These rounded nominal values may not precisely match your sensor dimensions, but your first request can use an Aspect Ratio more precise than the nominal 3:2 or 4:3.

Photo Aspect ratio. Aspect ratio calculator. Enter width and height. Aspect Ratio (short: A/R) is the width of an image or screen, divided by the height. In landscape orientation, the A/R is 1, for portrait orientation the A/R is. You have to consider the shape and size of the medium when making your aspect ratio calculations. But mostly, 16:9 is the common aspect ratio for videos. The aspect ratio of 16:9 makes it easier to move an element for your videos between projects and from place to place. How you will use a photo determines its aspect ratio. For instance, a. Simply enter the dimensions into the form above, select either pixels, inches or centimetres and hit the calculate button and you'll get the following information: How many megapixels your photo is How large you can print without losing quality The aspect it conforms to — even calculates closest aspect!

A calculator for the size of photos made with a digital camera. Here can be calculated, how the number of pixels changes, when the image is scaled or when the ratio of width and height is changed. At a change of ratio, either a part of the photo is cut off or the image will get distorted. Image aspect ratio and resizing calculator Work out image ratios and scale proportionally This is a simple calculator to help you work out the aspect ratio of an image, and the size of that image when it's resized, keeping the same proportions. That Aspect ratio can be entered in standard nominal format:
1:1 = a square image (image width same as height)
4:3 = 1.333:1 - Typical of compact camera and cell phone images
3:2 = 1.5:1 - Typical of DSLR camera images, and 35 mm film
16:9 = 1.778:1 - HDTV and movie video, typically 1920x1080 or 1280x720 pixels

which are rounded approximate nominal values. Or preferably more precise, it can be the corresponding divided number (image width/height, dimensioned as pixels or mm or inches) like the 1.5 or 1.3333 or 1.7778 ratio. Example: for 4:3 aspect, 4/3 = 1.3333. Because it can be the more precise number, like maybe 1.327:1. It is Not necessary to enter the :1 here (:1 is assumed if not), but you can enter it or not, or you can enter the format like 4:3. The actual precise value (like 1.329 or 1.503) may compute more precisely. More about aspect ratios.

Aspect Ratio Format — Example:

Aspect ratio 4:3 is 4/3 = 1.333, which can be entered as:

4:3 or 1.333:1 or 1.333 or as 1.338 if more precise.

Or 4288×2848 pixels is 4288/2848 = 1.5056:1 (images).
Or 17.3x13 mm is 17.3/13 = 1.331:1 (sensors or film).
Or 4x5 inches is 5/4 = 1.25:1 (prints).

The calculator will show the precise format, as like 1.333:1 format.

Three values of pixel dimensions may be shown, in the order of:

1. Exact computed dimensions (matches megapixels to show precision)
2. Rounded dimensions, like real pixels, but changes megapixels
3. Div8 values, pixel dimensions evenly divisible by 8 (is only one shown if already Div8)

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Div8 - Cameras actually use pixel dimensions which are evenly divisible by 8, no doubt to match JPG 8x8 compression blocks, which is the final result shown (I'll call it Div8 here, rounded up or down to that nearest match). Precise megapixels and aspect values obtained from the actual camera image dimensions should match it. But dimensions of any image scanned or cropped in your editor is unlikely to be evenly divisible by 8. If the initial pixel dimensions are not divisible by 8, then Div8 can't exactly match here.

There are two calculator options, and the results for each case are:

• The first option (Megapixels) calculation is the regular option. Calculated pixel dimensions (in gray text) are excessively shown out to a few decimal places (even if pixels cannot have fractions), to show that the megapixels come out exact, matching the same as entered.

Since images cannot be dimensioned in fractions of pixels, the rounded result is then shown (in green). Adding or Subtracting one pixel to width or height can be thousands of pixels in the other dimension, so the rounded result necessarily can affect the megapixel total somewhat.

• The second option (Image Size) is provided when pixel dimensions are already known, and might be all you know with any precision. It computes precise megapixels, and its purpose is greater precision, and of Aspect Ratio too. But the pixel dimensions must be integers, pixel inputs must be whole numbers. Pixel dimensions are exactly known and are typically 4 significant digits. Whereas megapixels and aspect ratio are rounded specifications, only two or sometimes maybe three significant digits (not totally precise). To recompute those four exact digits of pixel dimensions likely requires Megapixels and Aspect Ratio to also be four significant digits because in math, the final answer can only contain as many accurate significant digits as the least precise value computing it. So the computed pixel dimensions could be just a few pixels off, but a few tenths of a percent will certainly be close enough for practical purposes. The calculator is written for megapixels, but to aid seeing at least four accurate significant digits, the Image Size option was added to play with. It will show at least four significant digits, if applicable (fractional trailing zeros are not shown or needed).

Use of second option (Image Size): If checking that the calculator matches your cameras Div8 dimensions, the specifications for megapixels and aspect ratio are rounded nominal numerals which will be close, but might not compute the exact precise image size in pixels (due to rounding - camera specifications are rounded values.) If not exact, the best try the significant digits is to first enter the second option of actual sensor dimensions in pixels instead of Megapixels to compute the actual precise megapixels and aspect ratio values for your camera.

Then to aid using that result, there will be a Move Up button which will move these last computed precise values from Image Size up into the Megapixel option, for that purpose (you already have all the numbers then, but it then can recompute the same numbers from megapixels and aspect ratio).

Otherwise, Megapixels will work fine, and even better if you enter adequate higher precision for megapixels and aspect ratio. Since pixel dimensions are typically four significant digits, then to reach that same four-digit precision again, enter all values to at least four significant digits, if applicable. Four digits total are usually enough, but sometimes five digits can be better on Aspect Ratio. The Image Size option does compute sufficient precision from your dimensions. You can see in the initial default example, that 1.503 computes better than the nominal 1.5 below it (unless 1.5 happens to be the actual precise value).

This blue image shows the aspect concept visually. 4:3 is taller, but 3:2 is wider. The sensors all try to fit their diagonal to the lens diameter. However, the 16:9 video mode frames in photo cameras are normally necessarily contained within the dimensions of the existing 4:3 or 3:2 photo sensors. Then 16:9 cannot be the full diagonal (that video width cannot be wider than the sensor width). But their size is likely even a little smaller to optimize the subsampling, because 16:9 HD movies are typically output as 1280x720 or 1920x1080 pixels, which is 0.92 or 2.07 megapixels. Since specifics are not known here, 16:9 is computed on this page as a camcorder, independent of any still frame size.See More about maximum video frame sizes relative to still pictures.

Again, camera megapixels and aspect ratio are said as nominal rounded values. But these two values are just a multiplication and a division of the pixel dimensions, and as explanation of the precision offered, the second Image Size option was added to show those actual more precise computed values. They also show the difference from the nearest standard nominal aspect ratio (if in range). The few tenths of a percent of difference is not a big deal in practice. See the Aspect Ratio page.

The goal is to compute maximum dimensions of a specific aspect ratio that matches the specified megapixels. Megapixels is sensor Area (in units of pixels). Pixels are the only units used. The calculator computes the Width x Height image pixel dimensions of various aspect ratios that match the megapixels that you specify.

The terms kilobytes and megabytes and gigabytes were corrupted to mean multiples of 1024 bytes, necessarily used for memory chip sizes (including memory cards, USB flash drives and SSD, which are all memory chips), but sadly, 1024 is also commonly used for file sizes, which is unnecessary and counter-productive. The standard SI term mega means millions, defined as multiples of 1000. So mega in megapixels still correctly means 1000s, same way as humans count things. Same also for manufacturer's hard disk specifications in gigabytes (1000s), except our computer operating systems still sadly refer to size of hard drives and files as multiples of 1024. But megapixels is correctly units of 1000. No 1024 complications.

Math is precise, but Real World is sometimes less so: If checking the calculator against your camera, realize that cameras round their specifications, which affects precise calculations. For example, a Nikon D800 camera specifies 36.3 megapixels and we assume a DSLR nominal 3:2 aspect ratio. That computes 7376 x 4920 image size. Close, but its actual is 7360x4912 pixels which computes 36.152 megapixels and 1.498 aspect ratio, which does then compute the correct image size. If you enter the actual correct numbers, the calculator should show the exact dimensions.