the photography collection

Proportional Calculator

When getting an image or part of an image enlarged, it is important that your crop marks are correctly proportioned to match our print sizes. Sizing the crop marks correctly when you make them is easy using this calculator, and a little trial and error. [Crop marks are red lines drawn on an image to define a specific area].

Estimate where your crop marks will be and enter the dimensions in boxes A and B. Enter a dimension from the list of available sizes [shown below] in the C or D box. Put an X in the remaining box, and then click on "calculate" to find the other dimension of your enlargement, and to see how it will fit on the paper. [Works with inches or centimeters].

Original
  
Enlargement
A  Height
  = 
C  Height
B  Width
  = 
D  Width

AVAILABLE SIZES

5" x 7" (12.5 cm x 17.5 cm)
8" x 10" (20 cm x 25 cm)
9" x 11" (23 cm x 28 cm)
11" x 14" (23 cm x 25 cm)
12" x 18 (32 cm x 45 cm)

$12.00
$15.00
$20.00
$25.00
$32.00


16" x 20" (40.7 cm x 50.8 cm)
20" x 24" (50.8 cm x 61 cm)
24" x 30" (61 cm x 76.2 cm)
24" x 36" (61 cm x 91.4 cm)
30" x 40" (61 cm x 101.6 cm)
40" x 50" (101.6 cm x 137 cm)

$40.00
$50.00
$65.00
$80.00
$95.00
$140.00

If the height/width proportions of the enlargement you request differ from the print sizes shown above, the margins may not be uniform. A panoramic image may not fill the vertical space on the paper, leaving huge white gaps at the top and bottom.

If you are trying to match the size of a particular frame, you can use the calculator above in reverse. Measure the frame, and use those measurements in the A and B boxes. Measure one side of the area you would like enlarged, and enter the number in the C or D box. Calculate for X, and use the C and D numbers to make your crop marks.

By the way, the calculator works offline, if that's a concern.

Email us at photosales@denver.lib.co.us, or call 720-865-1818 for other questions about proportions, enlargements, and crop marks. Here's more about enlargements and image resolution.