Ninety or Ninty – Which is Correct?

Spelling out numbers is no easy task.

The good news is that most of the time, there is little reason to do so. Many style guides recommend that numbers greater than ten be represented numerically. Thus, you would want to use 90 instead of the word ninety.

Still, writers should be well-versed in spelling. Is it ninety, or ninty? Numbers in English do not follow a universal set of spelling conventions, so it can be difficult to know how to spell larger numbers.

What is the Difference Between Ninety and Ninty?

In this post, I will compare ninty vs. ninety. I will outline which spelling is correct and demonstrate how to use it in sentence examples.

Plus, at the end, I will show you a helpful mnemonic device that you can use to decide whether you should use ninty or ninety to describe quantities more than eighty-nine but less than ninety-one.

When to Use Ninety

Spelling of ninety: Ninety is a number, being defined as one more than eighty-nine. It is, therefore, also one less than ninety-one.

Ninety is represented numerically as 90. This number is important in geometry and science—right angles have 90 degrees, and 90 is the atomic number of the element thorium.

An isotope of the metal strontium has an atomic weight of 90 and is a radioactive product of nuclear fallout. It can sometimes be found in milk in the aftermath of a nuclear disaster.

Most of the time, you should represent numbers larger than ten numerically, e.g., 90 instead of ninety.

Still, here are three examples of ninety in a sentence,

• There are ninety feet between the bases of a full-size baseball diamond.
• “You have exactly ninety seconds to apologize to me for what you just said,” Jamie threatened vaguely.
• The latest employment report from the Labor Department, which came out a couple of weeks ago, showed that payrolls rose by just ninety-eight thousand in March, the lowest figure since last May. –The New Yorker

Also, if your sentence begins with the number itself, you should always spell it out.

• Ninety percent of workers want a tax cut.

When to Use Ninty

Ninty is a misspelling of ninety. You should not use it.

It is easy to understand why people make this mistake—there is not a universal rule for spelling numbers in English. The product of the math problem 4×10, for instance, is forty instead of fourty, and 5×10 is fifty instead of fivety. It might make sense for 9×10 to be ninty, but the correct spelling is actually is ninety.

English isn’t the only language with strange words for numbers. The French write out the number 90 as quatre-vingt-dix, which translates to four-twenty-ten. Ninety-nine in French is quatre-vingt-dix-neuf, or four-twenty-ten-nine.

Trick to Remember the Difference

Since ninty is never the correct spelling, remember ninety vs. ninty is easy. Ninety is always the correct way to spell the written form of the number 90.

Many style guides recommend using figures instead of words for numbers greater than ten. The AP Stylebook, for instance, requires all numbers 10 and above to be written as figures.

Since ninety is much greater than ten, it would be good practice to represent ninety as 90 in most cases.

If, for some reason, you need to write out the entire word, remember that ninety and nineteen both contain the complete word nine.

Summary

Is it ninety or ninty? Ninety is the written form of the number 90, such that it is one more than 89 and one less than 91.

• Ninety is the correct spelling.
• Ninty is a misspelling.