Use “comparison with” for direct, side-by-side contrasts, and “comparison to” for saying one thing is like another.
People often pause at a sentence like “a comparison ___ last year’s results.” Both to and with can sound right, and spellcheck won’t rescue you in most drafts. If you’re stuck on comparison to or comparison with, start with the rule below.
This guide gives you a clean rule, real sentence templates, and quick editing checks. You’ll also see what major references say.
Fast Rule You Can Apply In One Pass
If you’re contrasting two real things—numbers, plans, products, time periods—use comparison with. If you’re likening one thing to another—often an analogy or “X is like Y” move—use comparison to.
| What You’re Doing | Best Choice | Quick Cue |
|---|---|---|
| Side-by-side contrast of two items | comparison with | Both items stay distinct |
| Comparing two sets of data | comparison with | Numbers, charts, time periods |
| Choosing between options | comparison with | Trade-offs, pros and cons |
| Measuring change across time | comparison with | “This year vs last year” |
| Noting similarities as likeness | comparison to | “Like,” “as,” or analogy vibe |
| Using a metaphor to explain | comparison to | One item framed through another |
| Making a literary or rhetorical link | comparison to | Imagery, figurative language |
| Stating equivalence in a formula | comparison with | Two sides weighed directly |
The table gives the default choice that fits most academic and professional writing. Next, you’ll see why this pattern exists, plus quick ways to spot the sense you mean.
Why “To” And “With” Feel Different
In everyday English, with often signals pairing: two items placed next to each other. That matches the common meaning of comparison as a measured contrast.
To often signals direction or relation: one thing pointed toward another as a reference. That matches the common meaning of comparison as a likeness or analogy.
Writers mix them because “compare” itself has two related senses. You can compare things to find differences and similarities, or you can compare one thing to another as a way to say it resembles it. Prepositions follow the sense you mean.
Comparison to or Comparison With In Formal Writing
In formal writing, editors usually want the contrast sense to read cleanly. That’s why you’ll see comparison with used heavily in research papers, reports, and business memos.
Use “Comparison With” For Measured Contrast
Pick comparison with when the sentence could be rewritten as “set beside” or “measured against.” This is the safer choice for data, performance, cost, and outcomes.
- “A comparison with the 2024 baseline shows a sharper drop in errors.”
- “The study includes a comparison with similar trials in older adults.”
- “A comparison with competitor pricing reveals the gap.”
Notice the feel: two things stay separate, and the writer is weighing them directly.
Use “Comparison To” For Likeness And Analogy
Pick comparison to when the sentence is about resemblance, analogy, or figurative framing. This choice often appears in speeches, essays, reviews, and narrative writing.
- “Her mentor offered a comparison to a lighthouse in heavy fog.”
- “The author’s comparison to chess fits the plot’s slow tension.”
- “That comparison to a ‘reset button’ makes the policy sound simple.”
These lines don’t weigh two items as equals. They use one item to make the other easier to grasp.
Quick Tests When You’re Unsure
Swap In “Like”
If you can rewrite the sentence with “like” or “similar to” and it still means the same thing, to is often the better pick.
Try it: “His comparison to a marathon helped the class.” → “His comparison was like a marathon.” It still works.
Ask If You’re Evaluating
If the sentence is judging performance, cost, quality, or change, you’re probably evaluating. Evaluation pairs naturally with with.
Try it: “A comparison with last quarter clarifies revenue.” That’s evaluation.
Check What Comes After The Phrase
When a noun phrase follows (“a comparison ___ X”), the writer often means contrast. That leans toward with. When the line grows into imagery or a claim of likeness, it leans toward to.
What Major References Say
Dictionaries and style references often describe the same split: compare with for measured contrast and compare to for likeness. Merriam-Webster’s usage notes give a clear explanation of the two senses, and the examples match the rule above. See Merriam-Webster’s compare with vs compare to usage note for a concise summary.
For academic style, many instructors prefer the contrast sense in research writing. If you follow APA style, you’ll often see “compared with” used for study results and group differences. The APA Style grammar guidance isn’t a one-line rule on prepositions, yet it reflects the same preference for clear, literal wording in reports.
Common Sentence Patterns That Stay Clean
Data And Research
These templates fit lab reports, surveys, and term papers:
- “In comparison with Group B, Group A showed…”
- “The results allow a comparison with prior research on…”
- “A direct comparison with the control condition indicates…”
Business And Work Writing
These templates fit emails, decks, and proposals:
- “A comparison with last month’s spend shows…”
- “We ran a comparison with three vendors.”
- “This plan improves in comparison with the earlier draft.”
Literary And Opinion Writing
These templates fit reviews and essays:
- “The poet’s comparison to winter light carries…”
- “That comparison to a slow leak lands because…”
- “She draws a comparison to her childhood town.”
Two Tricky Spots Writers Hit
“Compare X With Y” Vs “Compare X To Y”
So far we’ve used the noun form: “a comparison with/to.” The verb form works the same way, yet you’ll see more variation in published writing.
When the action is measured contrast, “compare with” reads precise: “Compare the two charts with each other.” When the action is likeness, “compare to” reads natural: “People compare her voice to silk.”
Some editors accept “compare to” even for contrasts, especially in American English. If your goal is to avoid edits and margin notes, keep “with” for contrasts in formal text.
“In Comparison To” Is Common, But Check Your Meaning
Many writers default to “in comparison to” as a fixed phrase. It’s common in conversation and journalism, and it often slips into reports. If the meaning is true contrast, “in comparison with” may read tighter.
Here’s a clean revision move: if you wrote “in comparison to last year” and you truly mean a measured difference, switch to “in comparison with last year.” If you mean resemblance, keep “to.”
Editing Checklist For Clean, Consistent Usage
Run these checks during your final edit. They’re fast, and they catch most awkward lines.
- Name your intent: contrast or likeness?
- Look for numbers: if data appears, lean to with.
- Look for imagery: if the line works as “X is like Y,” lean to to.
- Keep it consistent: if one paragraph uses contrast, don’t flip prepositions without a reason.
- Read it out loud: your ear catches clunky preposition chains.
Mini Examples You Can Copy
Use these as quick models, then swap in your nouns:
- “A comparison with last semester’s grades shows steadier progress.”
- “In comparison with the earlier method, this one saves steps.”
- “Her comparison to a dimmer switch helped the class grasp gradual change.”
- “That comparison to a ‘shortcut’ oversells what the tool can do.”
When A Teacher Or Editor Prefers One Form
Language rules can be style choices. If a teacher, editor, or house style says “use comparison to,” follow that rule for that context. Your goal is clear meaning and smooth reading, not winning a preposition debate.
If you don’t have a style rule, the contrast/likeness split is a strong default. It keeps your writing consistent and reduces the chance that a reader misreads your intent.
Mistakes That Trigger Red Ink
Most slips happen because writers pick a preposition by habit, not by meaning. These quick patterns cause edits and confusion.
Using “To” For Data Contrast
Time-based lines like “in comparison to last year” often report a real difference. For measured change, “with” reads cleaner.
- Less clean: “Sales rose in comparison to last year.”
- Cleaner: “Sales rose in comparison with last year.”
Using “With” For Likeness
If the goal is resemblance, “with” can make the line sound like an audit. Switch to “to” when the sentence means “like.”
- Less clear: “Her courage invites comparison with a storm lantern.”
- Clearer: “Her courage invites comparison to a storm lantern.”
How To Stay Consistent In Longer Writing
Run a fast search for “comparison” before you submit. If the sentence carries numbers, categories, or a direct “vs” idea, choose “with.” If it carries imagery, choose “to.”
Phrases You’ll See In Published Writing
You may run into fixed phrases that look different from the “noun + comparison” pattern. They still follow the same contrast-or-likeness idea.
- Compared with: a tight verb form used in reports. “Compared with 2024, costs fell.”
- Compared to: common in speech and journalism. Use it for likeness, or keep it if your editor prefers it.
- As compared with: formal and a bit heavy. If the sentence feels long, drop “as” and keep “compared with.”
- In comparison with: works well when you want the noun form. It pairs cleanly with time periods and categories.
- In comparison to: common as a stock phrase. Switch it to “with” when the meaning is measured contrast.
If you’re editing for clarity, the simplest move is to pick one form in a section and stick to it. A results section can run on “compared with” all the way through. A reflective essay may use “comparison to” once or twice, then move on.
Second Table: Choose The Right Preposition By Context
| Context | Preferred Phrase | Example Fragment |
|---|---|---|
| Charts, results, metrics | comparison with | with the baseline |
| Prices, bids, budgets | comparison with | with competitor rates |
| Before/after changes | comparison with | with last quarter |
| Reviews, criticism | comparison to | to earlier classics |
| Metaphor or analogy | comparison to | to a safety net |
| Personal reflection | comparison to | to my first job |
| Side-by-side choice | comparison with | with two options |
Wrap-Up: A Simple Habit That Prevents Most Errors
Before you hit publish or submit, pause at each “comparison” phrase and ask one question: are you weighing two real items, or saying one thing is like another? That tiny check usually picks the right preposition on the spot.
If you want a short memory hook, use this: with pairs items for direct contrast; to points to a likeness. Use that, and your sentences will read clean in both everyday and formal writing.
One last detail: if you’re writing about the phrase itself, keep the wording consistent. As a quick meta check, you can say “I’m unsure about comparison to or comparison with,” then run the same contrast-or-likeness test on your own sentences.