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PhD vs Ph.D. — The Correct Abbr. for “Philosophiae Doctor”

PhD vs Ph.D. — The Correct Abbr. for “Philosophiae Doctor”

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Remembering abbreviations is naturally difficult especially when the expressions involved are particularly used within specific language communities.

But, in fact, there are a lot of abbreviations out there that you must already be familiar with, just like some internet slang terms such as “TBH,” “SMH,” and “TGIF.”

While this is the case, many other abbreviated expressions that are mainly used in formal contexts remain elusive, just like the abbreviation for “Philosophiae Doctor.”

The question of whether we should use “PhD” or “Ph.D.” is causing some confusion among cybercitizens at present, which is why we are addressing it in our post today.

Let’s start with a short answer to our inquiry.


What is the correct abbreviation for “Philosophiae Doctor”?

In American English, the standard practice is to use “Ph.D.” – the one with the periods; whereas “PhD” – the one without the periods – is mainly used in British English.


The meaning of “Philosophiae Doctor” in a nutshell

The term “Philosophiae Doctor,” otherwise known as “Doctor Philosophiae,” is the Latin equivalent of “Doctor of Philosophy.”

This is a title given to a person who has gained the highest degree or qualification in the academic world.

More importantly, having this achievement entails completing a doctorate program under a specific field in an accredited institution rather than an unaccredited one.

Undoubtedly, you would not want to gain your doctorate degree in so-called “diploma mills” because that would automatically undermine your educational integrity. 

Diploma mills are organizations that are unable to keep up with the best educational practices in a certain country; they may also offer illicit educational programs and degrees for a fee.

Before enrolling in a doctorate program, it is best to check whether the target school is accredited or quality-checked by official agencies.

In the USA, for example, the Council for Higher Education Accreditation (CHEA) is the one responsible for university accreditations.

In the UK, the Quality Assurance Agency for Higher Education (QAA) is responsible for the same role, albeit implementing a relatively different system.

Furthermore, those who are still taking up their doctorate programs are not necessarily referred to as doctors of philosophy just yet; instead, they are still considered candidates for the title.

The length of time and requirements needed to complete a doctorate degree may vary from one institution to another, as well as from one student to another.

So, it is always recommended to scrutinize these nuances beforehand, or else, one might end up in a compromising situation.

Now that we have discussed what it means to become a “Philosophiae Doctor,” let us now move on to the abbreviation part of today’s topic.

The next section elaborates on the abbreviation practices between American and British English language users.


Abbreviating “Philosophiae Doctor”: American vs. British English

One of the hardest-to-learn word-formation processes is word reduction, let alone remembering the symbols by heart and putting them into writing.

In morphology, a major branch of linguistics, the process of reducing words and phrases to conform to certain contexts is what we refer to as “abbreviation.”

The English abbreviation system is made up of several types, namely, acronym, shortening, initialism, and contraction.

One factor that makes abbreviations quite challenging is the difference in the practices between and among certain linguistic communities.

For example, the most common abbreviations in job advertisements include “WFH,” “Mktg.,” and “biz dev”; meanwhile, the popular ones in medicine are “a.c.,” “BKA,” and “GvHD.”

If these terms are not your cup of tea, then it is natural to get them mixed up if and when you encounter these abbreviations for the first time or when you don’t use them that often.

In other larger contexts, there are also some nuances as to how people use entirely the same language in two different geographical locations.

But, in reality, there are too many existing language communities that make use of English either as a native or a second language.

Hence, the next section only focuses on the difference between American and British practices regarding the topic being discussed.


“Ph.D.” is the American way

By and large, we have to steer clear of abbreviations if and when using them would cause communication issues.

That said, we must not use abbreviations on a resume just to save space, out of negligence, and even communicative convenience, for instance.

Whether or not periods appear in an abbreviation is also a noticeable grammatical nuance between American and British English.

American English users, as well as followers, are keen on using periods in abbreviated expressions, especially academic titles like “Ph.D.”

For example, the Chicago Manual of Style and the Canadian Oxford Dictionary both recommend using periods after “h” and “D,” thereby making “Ph.D.” the preferred version by most American English users.

Context is vital every time we have to use a language notwithstanding whether it is in spoken or written form because of the assumption that language is inherently ambiguous. 

This means that you would have to determine your target audience first before making the decision as to whether you have to insert or drop the periods.

If your written output is intended for language users adhering to American English, then it would be wise to place periods in “Ph.D.” to receive a favorable response.

But of course, this doesn’t mean that American English users will misunderstand your message if you omit your periods because the letters are utterly more meaningful than the punctuation marks in this context.


“PhD” is the British way

Generally speaking, the periods in “Ph.D.” are omitted among most English language users, which means that the problem as to whether to place the periods is chiefly trivial.

However, the practice of period omission in abbreviations is also something you would likely notice more in British English instead of American English.

In favor of the open-punctuation system, the periods in the abbreviated form of “Philosophiae Doctor” are omitted by British English users, thereby forming “PhD” instead. 

The trend nowadays is also moving towards the omission of periods, which means that punctuation marks are becoming less likely relevant in communication.

This can be attributed to the idea that the technological advancements in the modern world are happening at a break-neck pace and are unlikely to cease anytime soon.

This means that more and more communication modes are becoming available to us, thereby not limiting conversations to text and speech exchanges only.

The other existing communication modes include spatial, gestural, and visual ones — and these are indubitably more attractive than scripts and prints.


Capitalization rules on the abbreviation of “Philosophiae Doctor”

Remembering the complete form of certain abbreviations is already mentally tasking, which means that capitalization rules apparently add insult to the injury.

Therefore, the subsections below aim to address this concern in detail.


Capitalization within the abbreviation “PhD” or “Ph.D.”

As you may already figure, both “D” and “P” are capitalized but “h” is written in lowercase both in “PhD” and “Ph.D.”

This is because “P” and “h” are both parts of the word “Philosophiae” or “Philosophy,” while “D” is a separate initial standing for “Doctor.”

In referring to a person with a doctorate degree, the general format is to start with the complete name (i.e., first then last name) followed by the academic title which can either be “PhD” or “Ph.D.”

Depending on the communicative intent, the specific field that the person has graduated from may or may not be included when writing.

Commas generally come after abbreviations especially between names and academic titles no matter whether they are written as isolated entities or made part of sentences.

Here is an example of using academic titles as individual entities:


(correct) Blake Edison, PhD


(correct) Sarah Cole, Ph.D.

Do not precede the name with a name title if you are going to state the academic title after the name of the person to avoid redundancy.


(incorrect) Dr. Herbert Campbell, Ph.D.

Note that a comma must also come after the academic title if it appears either at the beginning or in the middle of a sentence.

Here’s a sentence using a person’s name with a doctorate title:


(correct) Philip Wilkins, Ph.D., provides free thesis consultation for undergraduate students twice a month as part of his educational advocacy.


(incorrect) A good friend of mine, Dr. Christine Stuart, Ph.D., retired from being the dean of the College of Arts and Sciences last year.


Capitalizing “PhD” or “Ph.D.” within sentences

Name titles or honorifics are capitalized by default when they precede the name of the person and are not used as a descriptive element in a sentence, such as in “Mr. Doe.”

The purpose of capitalization in name titles is to convey tact and respect toward the addressee, which is the standard practice in business and academic writing contexts.

In the case of academic titles, the general rule is to always capitalize them wherever they appear in a sentence.

Decidedly enough, obtaining a master’s degree is already not an easy task because it requires a lot of time and effort to get done, let alone completing a doctorate degree.

But more importantly, another purpose of the mentioned capitalization is to remove the ambiguities a reader might encounter upon reading abbreviations used within sentences.

Hence, the capitalization of name titles, as well as other known abbreviations, makes sentences more readable or intelligible.

Here are example sentences using “PhD” or “Ph.D.” only:


(correct) Valerie is a PhD candidate at MIT.


(correct) Potential Ph.D. students should consider their support system at home before enrolling in a program.

When in doubt, you can always use “PhD” as a default choice because it is the more common choice between the two.

But, there is also a need to remember that there is nothing wrong with using the periods in abbreviating the phrase “Philosophiae Doctor.”.

Apart from capitalization, pluralization rules on abbreviations also seem to be a tricky concern for some; hence, the last section below focuses on shedding light on this.


Pluralizing “PhD” or “Ph.D.”: PhDs vs. Ph.D.’s

Punctuation marks are generally avoided in British English, while punctuation marks are mainly preferred in American English.

That said, we can already assume that the use of “PhDs” is mainly a British practice, whereas the use of “Ph.D.’s” is substantially American.

Apostrophes are mainly used for contractions in British English, but these marks are used for both pluralization and contraction in American English.

Here are examples of using the plural form of “PhD” or “Ph.D.” in sentences:


(correct) My professor in translation holds multiple PhDs.


(correct) For my brother, people trying to obtain Ph.D.’s is quite an overkill. He even decided to quit his master’s program two months after taking classes.

But then again, it is worthy to note that either option would not necessarily cause misinterpretation to any target readers, hence a minor concern.

The only time that you may need to check for writing style guidelines is when you are submitting your output to authorities like publishing companies and institutional bodies.

In general, though, you can always go with either “PhDs” or “Ph.D.’s” in writing, but the more popular choice is, again, the one without the punctuation marks.

However, if you want to increase the formality of the message you are conveying, then you can go with the one that contains more punctuation marks.



Abbreviations, albeit tricky, are important elements that make communication faster and easier for groups of people that speak the same language.

But, we should also bear in mind (not “bare in mind”) that excessive and random use of abbreviations could meanwhile cause misinterpretation to outsiders.

Therefore, to make the most out of abbreviations, they have to be aimed at moderate and context-appropriate usage.


Frequently Asked Questions on “PhD vs. Ph.D.”


What do we mean by “DPhil”?

“DPhil” means “Doctor of Philosophy.” This abbreviation also serves a similar purpose as “PhD” or “Ph.D.”. These abbreviations are used to represent the highest academic title a person can achieve in an institution.


Are “PhD” and “DPhil” the same?

“PhD” and “DPhil” mean the same, although the former would lean more toward the complete Latin form which is “Philosophiae Doctor” and the latter being “Doctor of Philosophy,” if we are to look into the letter sequence. In general, “PhD” or “Ph.D.” is more widely used than “DPhil.”


Should there be a period after “r” in the abbreviation for “Doctor” and “Drive”?

In British English, no period comes after abbreviations of contracted words like “doctor” and “drive.” The opposite is true in American English, which means that the general practice is to use “Dr.” instead of “Dr” in writing.