To estimate the length of a paper, use the following guidelines. (Since the estimates have some inherent uncertainty, authors should be aware that the final invoice may have slightly different line counts.) All calculations are made in terms of single-column Physical Review (PR) lines; whenever a rule gives a line equivalent for a number of characters (letters, numerals, and spaces), it is to be understood that a partial PR line actually counts as a full line.

1. The title takes 4 lines for the first 86 characters and 2 lines for each additional 86.
2. Bylines take 2 lines for each 105 characters of an author-name group and 2 lines for each 105 characters of the corresponding address(es); 2 lines separate institutional groups. For bylines, no more than 60 lines are counted, provided all names are grouped together with all institutions listed below.
3. The receipt date takes 2 lines.
4. The abstract takes 2 lines for each 94 characters; 2 lines separate it from the receipt date, and 2 more lines separate it from the PACS numbers or text.
5. The listing of PACS numbers (and space below) is counted as 4 lines.
6. For the text of the manuscript, the average number of characters (letters and spaces) per manuscript line is estimated and converted to the number of PR one-column lines by the formula
   No. characters/avg. manuscript line
   ___________________________________ x No. manuscript lines = No. PR lines.
   No. characters/avg. PR line (=55)
7. A short displayed equation (less than 34 characters, excluding equation number; 40 if there is no equation number) with no built-up fractions (or matrices, 6-j symbols, etc.) takes 2.5 lines; built-up fractions take 3 lines, with parentheses 4 lines; matrices generally take 2-3 lines per row, depending on complexity. When the equation has both superscripts and subscripts another 1/2 line is added. A long equation, typed across two columns, takes double these amounts. When there are a number of two-column equations, intervening short equations may also be given two-column space. Short lines or groups of several lines preceding, following, and between equations are counted directly and included in the equation count.
8. Section headings take 1 line for each 40 characters. Two lines precede a heading, and 1 line follows.
9. Each reference takes 1 line for every 58 characters. Also, 4 lines separate the text and the references.
10. A figure that can be scanner-reproduced at one-column width (less than or equal to 3 3/8 inches wide) takes 7 lines per inch of final height; if it requires greater width, it takes 14 lines per inch of final height. (See the Information for Contributors regarding figures.)
11. Each figure caption takes 1 line for each 58 characters. Also, there is 1 line between a figure and its caption, and 2 lines between text and figure or caption (double these amounts if the figure requires greater than one-column width).
12. Each line (including double rules) in a table becomes 1 line for a table small enough to be typed in one-column width (58 characters including 3 spaces between columns of the table itself), 2 lines if it is wider. Two (or 4) lines separate text from a table or caption. A table caption is counted as 1 line for each 58 characters.