How to Cite a Diagram: APA, MLA and Chicago Examples

Knowing how to cite a diagram matters any time you drop a flowchart, graph, map, anatomical drawing or concept model into a paper, slide deck or lab report. A diagram is someone else's intellectual work just like a quotation, so using one without credit counts as plagiarism even when every sentence around it is your own. The good news is that the rules are predictable once you know which situation you are in and which citation style your instructor wants.

This guide walks through the parts of a diagram citation, then shows the exact layout for APA, MLA and Chicago, with short notes on Harvard and IEEE, special cases such as Google Images and lecture slides, and the mistakes that cost students points.

First, Decide How You Are Using the Diagram

The citation you need depends less on the type of diagram and more on what you did with it.

The Parts of a Diagram Citation

Whatever the style, a complete diagram citation draws on the same pieces of information. Collect them before you start formatting:

• Figure number: number figures in the order they appear in your paper (Figure 1, Figure 2), separately from tables.
• Title or caption: a short description of what the diagram shows.
• Creator: the person or organization responsible, such as an author, illustrator or agency.
• Source: the book, article, report or webpage that contains the diagram, with the page number if there is one.
• Date: the publication year, or "n.d." if no date is available.
• Location: a DOI or URL for online sources.
• Copyright status: the copyright year and holder, a Creative Commons license or a note that the work is in the public domain.

Keep any legend or key inside the image itself so readers can interpret symbols and colors without hunting through your text.

How to Cite a Diagram in APA Style (7th Edition)

APA treats every diagram, chart, graph, drawing and photograph as a figure. Each figure has four stacked parts:

1. The figure number in bold, flush left, above the image: Figure 1
2. The title one double-spaced line below, in italic Title Case.
3. The image, including any legend.
4. A note below the image beginning with the word Note in italics, followed by a period and the copyright attribution.

The attribution follows a set pattern for each source type. Use "From" for an unchanged diagram and "Adapted from" for a modified one:

• Journal article: From "Title of Article," by A. A. Author and B. B. Author, Year, Title of Journal, Volume(Issue), p. xx (DOI). Copyright Year by Name of Copyright Holder.
• Book: From Title of Book (p. xx), by A. A. Author, Year, Publisher (DOI or URL if available). Copyright Year by Name of Copyright Holder.
• Webpage: From Title of Webpage, by A. A. Author or Organization, Year, Site Name (URL). Copyright Year by Name of Copyright Holder.

For a public domain diagram, end with "In the public domain." For an openly licensed one, give the license, such as "CC BY 4.0." Here is a complete example using a fictional textbook:

Figure 2

Stages of the Water Cycle

[diagram]

Note. Adapted from Environmental Science: A Global Perspective (p. 112), by J. Rivera and M. Chen, 2021, Northfield Press. Copyright 2021 by Northfield Press.

The same source then appears in your reference list in the usual format: Rivera, J., & Chen, M. (2021). Environmental science: A global perspective. Northfield Press.

In your text, call out every figure by number, as in "Figure 2 shows how evaporation drives the cycle." Avoid phrases such as "the diagram above," because page layouts shift. If you discuss a diagram without reproducing it, cite the source normally with a page number, for example (Rivera & Chen, 2021, p. 112). For more on reference entries, see our APA style guide.

How to Cite a Diagram in MLA Style (9th Edition)

MLA labels figures "Fig." and places the label and caption directly below the image. You have two options for the caption:

• Full caption: give complete source information in the caption, written like a Works Cited entry but with the author's name in normal order. If the source isn't cited anywhere else in your paper, you don't need a separate Works Cited entry, though some instructors still want one.
• Short caption: give basic details such as creator, title and year, then include the full entry in your Works Cited list.

Fig. 1. The water cycle, from Jorge Rivera and Mei Chen, Environmental Science: A Global Perspective, Northfield Press, 2021, p. 112.

In your sentences, refer to it in parentheses, as in "(see fig. 1)," with a lowercase "fig." Tables are handled differently in MLA: they are labeled "Table 1" above the table, with the source given below it. Our MLA style guide covers Works Cited formatting in detail.

How to Cite a Diagram in Chicago Style

Chicago numbers figures and places a caption below each one, ending with a credit line that names the source. Common wording includes "Reproduced from," "Adapted from" and "Data from," and many instructors also accept "Source:" before the citation.

Figure 1. Stages of the water cycle. Adapted from Jorge Rivera and Mei Chen, Environmental Science: A Global Perspective (Northfield Press, 2021), 112.

If you use the notes-bibliography system, list the book in your bibliography as well. If you use the author-date system, the credit line can be shortened to (Rivera and Chen 2021, 112) with a full reference list entry.

Harvard and IEEE at a Glance

Harvard style varies between universities, so follow your school's guide. A typical version labels the figure below or above the image, such as "Figure 1: Stages of the water cycle (Rivera and Chen, 2021, p. 112)," and lists the source in the reference list.

IEEE, common in engineering and computer science, places "Fig. 1." and a caption below the diagram and points to a numbered reference, such as "Adapted from [4]." The full source then appears as entry [4] in your numbered reference list.

Special Cases Students Ask About

Diagrams From Google Images

Google Images is a search tool, not a source. Click through to the page that actually hosts the diagram, find the creator and publication details there and cite that page. If you can't identify where a diagram came from or who made it, choose a different one from a source you can verify.

Textbook Diagrams

Cite the textbook as a book and include the page number. If the textbook itself credits the diagram to another source, use the details given in that credit line.

Lecture Slides

If your instructor's slides contain a diagram, check whether the slide credits an original source and cite that if possible. Otherwise, cite the slide deck itself. In APA, that means the instructor as author, the year, the title with the description [PowerPoint slides] and the course site where classmates can access it.

Diagrams Made With AI Tools

Check your instructor's policy on AI tools first. Where they are allowed, credit the tool in the figure note and describe how you used it, and make sure every label and data point in the diagram is accurate, since generated images often contain errors.

Do You Need Permission to Use a Diagram?

For ordinary coursework submitted only to your instructor, you generally don't need the copyright holder's permission to reproduce a diagram for educational purposes, but you still need full attribution. Work that will be published or made public, such as a journal article or a thesis deposited in a university repository, is different: you may need written permission unless the diagram is in the public domain or carries an open license that allows reuse. In APA, add "Reprinted with permission" or "Adapted with permission" to the note only when you have actually obtained permission.

Common Mistakes When Citing Diagrams

• Writing "Source: Google" or pasting a bare URL under the image.
• Using "From" when you have modified the diagram, or forgetting to say it was adapted.
• Citing the diagram in the caption but leaving the source out of the reference list when the style requires it.
• Numbering figures out of order, or mixing figure and table numbers.
• Including a diagram without ever mentioning it in the text.
• Using an image so small or blurry that its labels can't be read.
• Following outdated rules, such as adding "Retrieved from" or a publisher's city in APA 7.

Quick Checklist Before You Submit

1. Every diagram has a number and title in the style your instructor requires.
2. Every borrowed diagram has a note or caption with the correct "From" or "Adapted from" wording.
3. Every source named in a note or caption also appears in your reference list, unless MLA's full-caption option applies.
4. Each figure is called out by number in your text, and the discussion explains what readers should notice.
5. Names, years, page numbers and URLs match the original source exactly.

Citing visuals is one part of a wider habit of crediting sources, which our guide on how to avoid plagiarism covers step by step. If you would like someone to check your figure notes, captions and references against APA, MLA or Chicago, our academic writing help page explains how tutors can review your formatting and explain each fix. You can also submit your paper for a citation review, compare tutor bids and choose the expert you prefer.

Frequently Asked Questions

Do I Need to Cite a Diagram I Made Myself?

No source citation is needed for a diagram you created entirely from your own ideas or results, though it still needs a figure number and title. If you built it from someone else's data, redrew it from a published diagram or based its structure on another model, credit that source in the figure note with wording such as "Data from" or "Adapted from" and list it in your references.

What Is the Difference Between From and Adapted From in APA?

Use "From" when you reproduce a diagram exactly as it appears in the original source. Use "Adapted from" when you have changed it in any way, such as redrawing it, removing parts, relabeling elements or combining it with another diagram. Both versions go at the start of the copyright attribution in the figure note, and the source also needs a reference list entry.

How Do I Cite a Diagram From Google Images?

Don't cite Google Images itself, since it only points to images hosted elsewhere. Click through to the website where the diagram actually appears, identify the creator, title, date and URL, and cite that page in your required style. If the hosting page doesn't show who made the diagram or where it came from, it is safer to choose a diagram from a source you can verify.

How Do I Refer to a Diagram in the Body of My Paper?

In APA, mention it by number, as in "Figure 3 shows the feedback loop," with a capital F. In MLA, use a parenthetical reference such as "(see fig. 3)." In every style, avoid phrases like "the diagram above" or "below," because layout can change. Every figure you include should be mentioned at least once in your text and explained.

Does a Cited Diagram Also Need a Reference List Entry?

In APA and Chicago, yes: the figure note or credit line gives the source details, and the full source also appears in your reference list or bibliography. MLA is more flexible. If your caption contains complete source information and you don't cite that source anywhere else, a Works Cited entry is optional, although many instructors still prefer you to include one.

How Do I Cite a Diagram From My Professor's Lecture Slides?

First check whether the slide credits an original source, such as a textbook or article, and cite that source if you can access it. If not, cite the slides themselves. In APA, list the instructor as author, the year, the slide deck title followed by [PowerPoint slides] and the course website or learning management system where the slides are posted.