The standard approximately abbreviation is approx., written in lowercase with a period at the end. It means "close to but not exactly," so "approx. 30 minutes" tells the reader to expect something near half an hour. You will find it on recipe cards, shipping notes, job listings, real estate flyers and lab reports.
When you read it aloud, say the whole word, approximately. In formal writing you usually spell it out, while forms, tables and labels, where space is tight, favor the short form. Symbols such as ~ and ≈ do the same job in math, science and quick notes.
Quick facts
Standard abbreviation
approx.Period
Yes in American English: approx.Capital letter
Only at the start of a sentence or label: Approx.Less common
appx., apprx., abt.Symbols
~ (tilde), ≈ (almost equal to)Used in
Recipes, forms, listings, schedules, data tablesNot to be confused with
ca. (circa) for dates, est. (estimated)
The approximately abbreviation and its options
| Form | Where it fits | Example |
|---|---|---|
| approx. | Most writing, forms, listings | approx. 1,500 sq. ft. |
| appx. or apprx. | Informal notes, some shipping and trade forms | appx. 12 lbs. |
| ~ | Quick notes, texts, charts | ~20 people |
| ≈ | Math and science | π ≈ 3.14 |
| abt. | Family history records | born abt. 1850 |
Of these, approx. is the one style guides and dictionaries list as standard. The others are understood but look less polished in formal work. For the general rules behind shortening words, see how to abbreviate.
Period, capitals and spacing
- Use the period. American English adds a period because the word is cut short: approx. British writers often keep the period too, though some drop it.
- Lowercase inside a sentence. "The trip takes approx. two hours."
- Capitalize at the start. "Approx. 40 guests are expected."
- Space before the number. Write approx. 10, not approx.10.
- One period to close. When approx. is the final word, its single period does double duty.
- No plural. Approximately is an adverb, so there is nothing to make plural.
Where you see approx. in real life
The short form shows up anywhere a number is a good estimate rather than an exact count.
On a home listing: "3 bed, 2 bath, approx. 1,800 sq. ft." The seller is saying the size is close to 1,800 square feet but may be off a little, so buyers should not rely on it as an exact measurement. See the square feet abbreviation for the second short form in that line.
- Recipes: "Bake approx. 25 to 30 min."
- Job ads: "Approx. 20 hours per week."
- Shipping notes: "Package weight approx. 4 lb."
- Event flyers: "Walk is approx. 3 miles."
Approx. vs ca., est. and about
Several short forms mean "roughly," but each has its own lane:
- approx. works with amounts, sizes, times and distances.
- ca. or c., from the Latin circa, is used with dates and years in history and art: "ca. 1800."
- est. means estimated, used for counts and costs not yet final. It can also mean established on a sign, as in "Est. 1952."
- about or around are the plain English choice for most sentences and need no abbreviation.
A quick check: if the number is a date, reach for ca. If it is a measurement, approx. is the safer pick.
When to write the full word instead
In essays, letters, news writing and school reports, spell out approximately or swap in about. Abbreviations in running text can look rushed. Keep approx. for tables, forms, captions, recipe steps, listings and notes where space and speed matter. On a school assignment, follow the teacher's style sheet; many ask for the full word. The common abbreviations section covers other everyday words you might shorten the same way, such as the etcetera abbreviation.
Sample sentences
- "The drive to the lake is approx. 90 miles."
- "Approx. half of the class signed up for the field trip."
- "Add approx. 1 tsp. of salt, then taste."
- "Delivery window: approx. 2 to 4 p.m."
- "We expect ~50 people, so order extra chairs."
Questions people ask
What is the abbreviation for approximately?
The standard abbreviation for approximately is approx., with a period. Informal notes sometimes use appx. or the tilde symbol ~.
Does approx. need a period?
In American English, yes. The period shows the word has been shortened. Some British writers leave it off, but approx. with a period is correct everywhere.
Is it OK to use ~ for approximately?
Yes, in notes, texts, charts and informal writing. In formal documents and essays, use approx. or write the full word.
What is the difference between approx. and ca.?
Approx. goes with amounts like weight, size and time. Ca., short for circa, goes with dates and years, as in ca. 1750.
How do you say approx. out loud?
Read it as the full word, approximately. Saying "approx" as a clipped word is heard in casual speech but sounds informal.