As we need reviewers for our own papers, at least two per manuscript, we should not accept less reviews than we need for our own papers. The minimum number of reviews we accept should ideally double the number of our own published papers per year.

If I publish 10 papers per year, I should accept a minimum of 20 reviews per year.

In my opinion, not more than three.

I received a lot of invitation from editors for review assignment, but I accept not more than two in a year.

In my own opinion, reviewing manuscripts is all about interest. You can be an expert in a particular field and you didn't have interest in paper reviewing, no matter the number of invitations sent to you by journal publishers and editors you won't honour any one of them just because of lack of interest. To me, to those that have created interest and wanted to contribute their quota to quality scientific publications and also in learning more and gaining expertise in their field of calling, you can honour invitations based on your availability to do thorough review of such manuscript(s).

Thank you

Olutosin

Many thanks Prof Subhash C. Kundu for your answer. You mentioned that you review two, and that is good to know.

Dear Md. Ashraf Uzzaman and Olutosin Ademola Otekunrin, thanks for your diverse opinions. But do you think that accepting invitations to review papers should be based on interests? I thought that people are invited based on their expertise?

Hello 

I think this matter depends on the availability of time. Not more than three or four per year. 

Liqaa 

It is more about the willingness of a person, still more, some Sciences may need an exceptional expertise so such experts may prefer to review a very few article. However in social sciences and Humanities the case is not so, hence can review a good number of papers.

It is very difficult to establish "a priori" a number of papers to review. In fact, accepting or reject to review a work paper depends on the curiosity and interest that arouses in me, and from my availability of time at the moment of the publisher's proposal. I normally receive a dozen referee proposals per year and generally accept no more than four.

I tend to agree with some of the others above, namely the absolute number is not fixed but varies depending on time available in your schedule or research plan, interest and capability.Some folk are good speed readers i.e. they can understand and retain the information or concepts. Others just skim the surface. The latter readers may do more reviews in a more superficial manner.

How many articles should a researcher accept to peer review in a year?

Think it depends on the researcher / reviewer's availability & preferences.  For my case it varies from 1-4 manuscripts per year inclusive some same manuscript that need to be reviewed for numerous times.  

Just want to share - beside the manual method, there is another way to track the manuscripts that you'd reviewed by submitting each thank you note / email from the journal editor where you'd reviewed their manuscripts into this website called Publons.  Also every time you'd completed a review, you will get some brownie points something like RG score - see Publons link below (you need to register first)

https://publons.com/home/

As expert in food science I do about 10-12 reviewing per year, decline to review from 20-30 manuscripts. 90% of accepting manuscript to review is accepted from the journal side. Never late to submit my reviewing because I think is a business must done correctly. 

Best regards

Aly R Abdel-Moenin

At best 5-7 not more then

Difficult to answer that question because we are invited because of our expertise but time constraint is a big issue! If you accept to do it, you really have to do it properly.

Hello Emeka W. Dumbili,

I think one article per month does not hinder the reviewer. Of course, if the reviewer  has more time, he can review two articles per month, without compromising the quality of the review.

The number of paper one should review in a year will vary and it is not possible to fix a number for everyone. It depends on experience, availability of time, quality and length of paper. I usually get several review invitations every month but for review, I accept only one paper of my interest  and expertise in a month.

Many thanks Prof Yogesh for your answer. That means you review about 12 papers yearly. You are doing a great community service. 

Thanks Prof Anton for your answer. Reviewing 12 papers annually may be daunting, especially for some scholars working in difficult environment. 

Although I am retired scientist, I prefer to review 5-6 articles in a year  

As much as you submit it yourself to be fair.

Thanks Prof Mushtaq for your answer. Please how many review invitations do you advise an early career researcher to accept in a year? I receive too many invitations, so I am not sure whether there are implications of saying no, especially to journals that I have not published in  (but have plans to submit to such journals).

thanks  all professors those who have given  the answer.12 months 12 review it is very difficult and doesn't make sense more

Four reviews per year should be fine.

I usually accept reviewing assignments for not more than three articles a year.

My self around 4 to 5. It depends on the article of my interest also.

Not more than 2

As the year has 4 seasons, I say 4. Reviewing 4 articles still can make fun and adds to fairness in judgement. Otherwise, an exhaustion of the reading potential might set in.

Many thanks Prof Mahfuz for your answer. 

Thank you Dr Anthony for your opinion. 

Thank you very much Dr Stephen. I like the fun part of your answer. In fact, I asked the question because review invitations seem to be reducing my fun. 

Depend on the availability of time and other commitments. But should not be more than 4. Otherwise difficult to do justice. 

I usually accept reviewing papers for not more than Four articles a year (Three Months ONE)

As we need reviewers for our own papers, at least two per manuscript, we should not accept less reviews than we need for our own papers. The minimum number of reviews we accept should ideally double the number of our own published papers per year.

If I publish 10 papers per year, I should accept a minimum of 20 reviews per year.

Many thanks Dr Nishad! 

Thanks Prof Ronald for your selfless suggestion. It means to treat others the way you want to be treated. 

I think it should be accepted whenever you have time and competence to review. A bare minimum would be the equivalent of the strain you yourself put on the review pool - i.e. based on the number of reviews you recieve for submissions in a year. That would be at least 2x the number of submissions (minus the number of desk rejects), usually more, since there are commonly more than one round of reviews - I expect the lead author of each paper to take responsibility for such a compensation. When a less experienced researcher is the lead author, the supervisor should make sure to review the equivalent number of papers. Anything less would be more-or-less parasitic, making other people work harder than they should have to. However, it is important to not accept when there is no time - I think no one wants a poor 3-sentence review from a stressed person that didn´t have time to do it properly. Good and fair peer review is a service we expect to recieve whenever we submit a manuscript, so we should always make sure to fulfill our own part in it, so that others can have the same expectations.

In my opinion, the limit is related to the care and quality that we can give in the review work. It depends on the time and dedication of each one!

Many thanks Prof Joacim for your detailed comment. As you commented, it means that we should give as much as we receive. 

Thanks Prof Osmar for your helpful answer.

At least once a month.

Thank you

Olutosin

Usually I undertake to accept a new review for each article that I submit

Thanks Dr Wesley for your answer. Does it mean that if you don't submit for some time, you will not accept review invitations for that period? 

I am in the editorial board of 3 journals and 1 of them send me about 1 ms per month, but sometimes 2 or 3. In the last 5 years, I have served as referee for about 35 other journals, reviewing or editing more than 100 manuscripts. I used to accept mss whenever "I had time", but I have noticed that the quality of my work as referee have slightly decreased, so I just accept mss when I can really contribute to them. I used to spend about 10-15h revieweing a ms, but nowadays I spend ca. 4-5h per ms. When I am not able to accept, I mostly recommend post-docs or PhD students that are doing research in the field.

Thank you Prof Ricardo for sharing your experience. Your comment is very helpful. I am learning a lot from these comments. One has to accept an invitation to review a paper with the aim of doing a thorough review. 

I understand that researchers need to make an effort and increase the number of reviews. Editors should also include more young researchers as reviewers, many are already doing so. They should also include and give opportunities to researchers from around the world in the review.

As a rule of thumb, 2 to 3 times the number of papers you submit per year. That is because each paper you submit gets reviewed by 2 to 3 peers, so to keep the wheel  turning we should review 2 to 3 times more than submit.

Many thanks Dr Adrian for your emphasis on the rule of thumb. 

Maximum 2 or 3

Thank you Prof Barbara for your answer. Please like how many review invitations do you receive annually? 

At least 2 or 3 0not more then. Quality  does matter not quantity 

Dear Prof Barbara, thanks once again for sharing your experience. I was beginning to wonder whether multiple invitation is peculiar to early career researchers. Maybe editors feel that they have more free time. 

Many thanks Dr Vijayfor your detailed and helpful comment.

Reviewing is exactly similar to sport exercises, where some people are able to do hard and much exercises per day, so that means, there is no specific number of articles.

Regards, Emad 

Reviewing an article does need time. 4-5 articles a year are good enough.

Prof neelamadhab your absolutly  right 

Dear Prof Emad, thanks for your answer. Your analogy with sport exercises is intriguing. 

It's difficult to answer, but if I really have to answer, I will say 12 at the rate of one each month.

The maximum I have ever accepted in a year is 3, given my own teaching and research.

Estimating the work of other authors is highly dependent on the content of the particular text. I am completely convinced that it is almost impossible to estimate how many texts of other authors can one evaluate annually. There are many parameters that significantly influence the assessment

It is not ideal to set  a gauge on a particular number of reviews. it sure may depend on the primary assignment and other responsibilities.  It may be possible to  accept two reviews in a month if  available, since most  journals expect  reviewers to submit their reviews on an articles within 14-20 days.

Sometimes it may be practically impossible to attend to even a review work in a month, two or three months. It is better to decline than to give low quality review or delay the process by late submission of reviews.

 Having too many reviews in a month or year is an indication of poor quality review except the reviewer is employed  on a full time  basis. But as a volunteer, take on, numbers you can sacrifice time to handle effectively.

Thank you.

Many thanks Dr Olusola for your great contribution to this question.

It varies individual to individual depending on the interest,experience and availability of time,But whatever we review must be given appropriate time.

I agree with the views expressed by the Dr Syed and Dr Vijay Bhaskar. It really depends on the capability and availability of the researcher.

hello

Think 2 to 3 during the year

regards

I tend to accept most of the requests, but often end up replying with delay. Nonetheless, this never affected the quality of my reviews. I think this is a particularly important contribution to the society for a scientist.

I think Ronald's suggestion of multiplying by 2 the amount of papers we produce to find the approximate number of acceptable reviews makes a lot of sense.

Many thanks to you all for these great contributions. The suggestion of multiplying the number of your submission appeals to fair dealings. 

Thanks so much Prof Gianluca for your comment. You opinion is noted.

It is a very interesting question. However, there is not an established number of reviews per year. The decision of doing a review comes from the availability the researcher has to do a qualified review timely. It is not desirable accepting a review if you are not expecting to finish on time. Once you publish regularly, your name is available in internet for many journals, so you receive (according to your academic profile) many invitations (up to 10) during a given year to review manuscripts. However, acceptance comes with the responsibility of the researcher to respond timely with the expertise to editors and authors.

It depends on the availability of time and the topic of the paper. 

Many thanks Prof Haitham for your comment.

It depends on how much time and energy you might have.

As the Editor-in-Chief of 6 international journals, I handle at least 25 papers every week, and write reports on most of them.

It depends on how much time one can spare for review. Out of several review invitations, I normally accept 2 of my choice every month.

3-4 ?

4 articles

Four articles

If this is a rhetorical Question, please permit me to Answer it seriously with a different Question:

https://www.researchgate.net/post/How_long_is_a_piece_of_string

It depends greatly on how much time an academic is willing to devote to (honorary = unpaid) service to the academic community.

Open access journals usually require swift reviewing to reduce editorial turnaround time, which is reasonable as our own submissions can also be expected to be reviewed quickly.

I am the Editor-in-Chief of 4 international journals, and review around 15 papers on a weekly basis throughout the year.

I agree with the previous assertion by Prof. Dr. Chia-Lin Chang that “it depends greatly on how much time an academic is willing to devote to (honorary = unpaid) service to the academic community. ” Moreover, this also depends essentially on the quality of a journal where the paper is submitted. In my opinion, this number should be at most two with respect to papers submitted in leading international journals in a specific scientific area, and at most six with respect to papers submitted in other journals.

Many thanks Romeo for your comment.

Please why do you think we should do more reviews for other journals instead of leading journals?

Four articles .

As many as can be handled professionally.

Editors-in-Chief handle hundreds of papers every year, with many leading to desk rejection.