Equations

Equations should be integrated into the text of your disquisition and not grouped at the end of a chapter. Equations may be introduced and integrated into body paragraphs or placed at a natural break point (between paragraphs or at the top or bottom of a page) following their first in-text reference.

Examples of formatted equations with an equation number can be found in our example document of non-text items.

If you use a large number of equations in your disquisition, you should include a List of Equations in the prefatory material. Unless otherwise directed by the style manual of your discipline, including a List of Equations is optional. For information about how to format a List of Equations, see our wiki page on List of Tables, Figures, Schemes, Etc.

In the List of Equations, a brief title or description of the equation should be included in each entry. However, equations in the document chapters should not be given a title, and the equation should be described in your text.

Contents
  1. Formatting Requirements
  2. FAQ
  3. Issues
  4. Resources

Format Guidelines: Equations

  • Equation position – Equations should be centered on the page. (Using the requisite 1" margins, the center of the page is at 3.25".) Do not place equations within paragraphs, titles, or notes.
  • Number position – If an equation is numbered, the equation number should be flush with the right 1" page margin.
  • Numbering is optional – When you use several equations in your disquisition, you may want to number the equations to make it easy to reference them within the text. If you number one equation in the text, then you should number all of the equations that appear in the disquisition; if your disquisition contains proofs or series of equations, you may elect to number only the final step or product.
  • Number sequence – All equation numbers must be sequential. You can number the equations sequentially by chapter (such as 1.1, 1.2, 1.3, 2.1, 2.2, 2.3, etc.), or you can number them in order of appearance, regardless of chapter or section (such as 1, 2, 3, 4, and so on).
  • Number label – Equation numbers must be enclosed in parentheses: "(1)". You may optionally include the label “Equation” or “Eq.” in the parentheses before the equation number: "(Equation 3.2)" or "(Eq. 3.2)". If you include a label, you must use the same label for all equation numbers.
  • Font – The number of an equation must use the same font type and size as the paragraph text. The equation itself may use a different font, such as Cambria Math. All equations should use the same font. Variables, symbols, and functions referenced outside of equations may use the same font as equations or the paragraph text; choose one style and use it consistently. Operators and numerals outside of equations should always use the same font as the paragraph text.

Quick Answers

Numbering equations is optional, but if you choose to number equations then all equations should be numbered. However, some exceptions may be made. For example, if you have a series of equations that demonstrate how another equation is derived, numbering only the final equation makes more sense: it helps set it apart, and may be the only equation in the series that will be referenced elsewhere.

Including a List of Equations is optional. We recommend including a List of Equations whenever you use equations that are used across multiple pages or sections. Your readers may not read your document in order and they may not read it all at once; having a List of Equations helps readers find equations in your document when they find subsequent references in later parts of the disquisition, but want to reference them.

Issue: Equations Are Not Centered and/or Equation Number Is Not Flush with Right Page Margin

Requirements:

  • Equations should be centered on the page. (Using the requisite 1" margins, the center of the page is at 3.25".)
  • If an equation is numbered, the equation number should be flush with the right 1" page margin.

Without a number, equations can be most easily centered by simply using the alignment tool (Home tab). If your equation is numbered, use the steps and settings below to place a centered equation and right-aligned number on the same line.

  1. Place your cursor on the line with the equation, but outside of the equation editor.
  2. Open the paragraph settings for this line and use the following settings, also shown in the image below.
    1. Alignment: left
    2. Line spacing: single, with 0 pts before and 12 pts after
  3. Click the "Tabs" button at the bottom left of the paragraph settings dialog box to open the tab settings for the line. In the tabs settings dialog box, apply the following settings for two tab stops, also shown in the images below. After entering the settings for each tab stop, click "set" to save the settings.
    1. Position: 3.25", alignment: center, leader: none. This is the tab stop for the equation.
    2. Position: 6.49", alignment: right, leader: none. This is the tab stop for the equation number.
  4. Place your cursor in front of (to the left) of the equation and press the Tab key to move it to the first tab stop, centering it.
  5. Place your cursor in front of (to the left) of the equation number and press the Tab key to move it to the second tab stop, placing it against the right margin.

You can copy these formatting settings to other equations quickly using the Formatting Painter tool and its associated hotkeys. Alternatively, you may use a borderless three-column table to achieve a similar effect; however, you will need to do more manual adjustment, such as altering the table columns to keep the equation centered and removing the cell padding, and it's somewhat more tedious to reproduce the table across a number of equations than the method above.

Issue: Inconsistent Equation Font

Requirements:

  • The number of an equation must use the same font type and size as the paragraph text. The equation itself may use a different font, such as Cambria Math. All equations should use the same font. Variables, symbols, and functions referenced outside of equations may use the same font as equations or the paragraph text; choose one style and use it throughout the document.
  • All elements of the disquisition (including body text, tables, and headings) must appear in the same font type. Exceptions include the font that is used within figures, illustrations, equations, or other special elements; however, we recommend using the same font within images.

All equations should use the same font. Explanatory or supporting text with the equations can be in the same font your equations or your paragraph text. If a supporting or explanatory text is frequently included with your equations throughout your disquisition, use the font for your paragraph text. Variables, symbols, or functions referenced outside of an equation--such as in the paragraph text or a figure title--may use the font from your equations or the paragraph text. Numerals and operators outside of equations should be rendered in the same font as the paragraph text.

Additionally, do not use Word's equation editor outside of your equations, such as to place variables, symbols, or functions within paragraph text; doing so may cause issues with the tagging and display of your document. If you want to reference a variable, symbol, or function outside of an equation, you can add special symbols from the Insert -> Symbols menu, and other settings can be formatted directly from the text's font settings, such as superscripts, subscripts, or typeface.

Ex.: Two acceptable font schemes for an equation. (Note: non-italicized text indicates paragraph font and italicized text indicates equation font.)

Y = Mx + B, for all x (1)

r2= x12 + x22, for all x (2)

In equation 1, the text "Y = Mx + B" and "x" is in the equation font, whereas the text "for all" is in the paragraph font. In equation 2, all of the text is in the equation font; since there is little supporting text, it can be in the equation font. If your document frequently employs supporting text within equations, you should use the style for equation 1.

In general, we recommend using the style of equation 1, as it demonstrates to your readers that equation-specific text will be in a special font, but either method is acceptable. Choose one style and apply it to all equations in your document.

Ex.: Two different and acceptable font schemes when referring to variables, symbols, or functions in the paragraph text. (Note: non-italicized text indicates paragraph font and italicized text indicates equation font.)

  • "In equation 1, M = 1 and B = 5. This yields the data in table 1 ..."
    • The symbols/variables are in the equation font, whereas the rest of the text is in the paragraph font, since it is not a variable, symbol, or function. Operators and numerals outside of equations should be rendered in your paragraph font.
  • "In equation 1, M = 1 and B = 5. This yields the data in table 1 ..."
    • All of the text is in the paragraph font.
  • "In equation 2, x1 = 4 and x2 = 3, which therefore means r = 5."
    • The symbols/variables are in the equation font, whereas the rest of the text is in the paragraph font. While the subscripts for x are numerals, they are part of the symbol/variable, and therefore rendered in the equation font.
  • "In equation 2, x1 = 4 and x2 = 3, which therefore means r = 5."
    • All of the text is in the paragraph font. See the style guide for your discipline for specific conventions for formatting symbols, subscripts, and superscripts, such as the use of italics.

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