Per Month vs. Monthly – What’s the Difference?

Is there really a difference between “monthly” and “per monthly”? Are these just different ways to say the same thing, or is there some small, yet important distinction?

In this post, we will discuss the difference between the two.

Per Month vs. Monthly – What’s the Difference?

Per month and monthly are very similar. Both are used as a framing device to provide context to a sentence based on time. “Per month” can be used to describe how something must be done a number of times every month, while “monthly” means something must be done every month.

Admittedly, that difference is very minor, and it can be a bit confusing too. The main difference is whether or not you are describing how often something is done every month, or if you are describing the fact that something is done every month at all.

Consider the following examples:

• I go grocery shopping twice per month.
• I go grocery shopping monthly.

The first sentence uses “per month” to state how many times you go shopping each month. The second sentence uses “monthly” to state that grocery shopping is something that you do every month, but does not say anything about how often you do it every month.

Now, you can use “monthly” in place of “per month”, but you cannot always use “per month” in place of monthly. It only makes sense to say “per month” if you provide a number to go along with it (once, twice, etc.).

For example, look at the following sentences:

• Correct: I go grocery shopping twice monthly.
• Incorrect: I go grocery shopping per month.

The first sentence still makes perfect sense, providing a complete idea. But the second sentence no longer makes sense, because “per month” should inform someone how many times something is done within the span of one month, but this sentence offers no such information.

Per Month

“Per month” is a phrase used to describe how often something is done in the span of one month. It must always be accompanied by a number of times something is done, such as “once, twice, etc.”.

You do not use per month to imply that something is done every month, but to specify how many times it is done every month.

Consider the following examples:

• Correct: Jane buys new clothes three times per month.
• Incorrect: Jane buys new clothes per month.

In the second sentence, “per month” makes no sense, because it is supposed to be used in tandem with a statement about how often something is done. The first sentence provides that needed context, and is therefore correct.

You must always provide a number to go along with “per month” in order for it to be correct. You do not use “per month” just to say that something is done every month, without any mention of how often within that span of time it happens.

Monthly

“Monthly” is a word that describes a span of time, that span being “one month”. If you do something “monthly”, that means it you do it every month. However, monthly does not necessarily have to state how often something is done every month, only that it is done every month.

That said, it can also be used in the same way as “per month”, if you do want to state how many times a month something is done. It is just not strictly necessary.

Consider the following examples:

• Jordan washes her car monthly.
• Jordan washes her car four times monthly.

The first sentence simply tells us that Jordan washes her car every month, but offers no detail besides this. The second sentence tells us that Jordan washes her car a particular number of times every month. Both are correct, they just offer different information.

Conclusion

“Per month” is used when describing how often something is done every month, as in “twice per month”.

“Monthly” can also be used to do this, but it can also be used just to state that something is done at all every month, without any specification as to how frequently.