Mold vs. Mould: What’s the Difference?

Americans and the British spell many words differently. Americans omit the U that appears in some British words as a second vowel directly before a consonant. This rule doesn’t extend to every such word, though, so it can be confusing to remember which words have different spellings.

Mold and mould are alternative spellings of the same word. Continue reading to find out in which context each would be appropriate.

What is the Difference Between Mold and Mould?

In this article, I will compare mold vs. mould. I will use each spelling in a sentence and explain its proper context.

Finally, I will discuss a helpful trick to use when you aren’t sure whether to choose mould or mold in your own writing.

When to Use Mold

mold versus mould spellingWhat does mold mean? Mold can be a noun or a verb.

As a noun, mold sometimes means a fungus that grows on organic matter. You can see the word mold used in this sense in the following sentences.

  • I wanted to eat the quiche I made two weeks ago, but it had mold on it.
  • Mold grew on the damp wood in the frame of the house.

Mold can also mean a container that shapes molten liquid as it solidifies, like in these sentences:

  • The machine poured the iron into a mold, to form its final shape.
  • We need a new mold for the redesigned parts.
  • The shop bends flat glass by placing it on a mold — the company has 4,000 shapes — and heating both pieces in a kiln. This causes the glass to soften and slump into the desired shape. –The Washington Post

Sometimes, mold is used figuratively to refer to a recognizable convention or form. See the examples below.

  • The new author is very much a dramatist in the mold of his 17th century British forebears.
  • The candidate broke the mold for campaign financing.

As a verb, mold means to form something into a new shape. The sentences below are examples:

  • I will mold you into a new woman.
  • Take your anger and mold it into determination.

When to Use Mould

Definition of lit definition of lighted definitionWhat does mould mean? Mould is a British English spelling of mold. It is used in all of the same contexts as mold.

Where Americans use mold, British English writers would use mould. The words differ only in the language communities in which they are accepted.

  • At one time they were made in a variety of sizes and in decorative moulds of different shapes. –The Guardian

In the ngram below, you can see the usage of mold and mould in both American and British English, respectively.

molding or moulding

moulding or molding

These graphs chart words used in books written in English since 1800. Even though they are not scientific or precise, they can easily illustrate long-term trends in usage.

Trick to Remember the Difference

Here is a helpful trick to remember mould vs. mold.

It’s easy to remember whether to use mold or mould.

  • Mold is the preferred spelling in American English.
  • Mould is preferred spelling in British English.

Since mould contains a U, like United Kingdom, you can easily keep these words straight in your mental vocabulary.

This goes for all variations of mold/mould.

For example,

  • Crown molding = American English
  • Crown moulding = British English


Is it mold or mould? Mold and mould are alternative spellings of the same word, which can refer to fungus or a container for molten liquid as a noun, or the act of shaping something as a verb.

Americans use mold, but the British use mould.

You can remember to use mould in the U.K. since both mould and United Kingdom contain a U.

Now that you know the difference between these two words, be sure to check this site for all your other word choice questions.