English UsageComparison guide
Mold vs. Mould
“Mold” and “mould” are regional spellings across the documented noun and verb senses: Cambridge labels mold as the US spelling of mould.
Use “mold” in US English and “mould” in UK English for the corresponding ordinary noun and verb senses.
Key details
Confusion Familyregional-spelling
Rule Familyregional-orthography
Termsmold, mould
Variant Scope“Mold” and “mould” are regional spellings across the documented noun and verb senses: Cambridge labels mold as the US spelling of mould.
Further guidance
Core difference
Use “mold” in US English and “mould” in UK English for the corresponding growth, container/shape, and shaping senses.
Fast Test
Match the form to the intended meaning, regional convention, or required house style, then keep that choice consistent.
Variant Boundary
This pair is a spelling variation, not a general meaning contrast; specialized proper names or house styles can still control.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Mold — Cambridge Dictionary (opens in a new tab)Cambridge Dictionary · US spelling of mould
- Mould — Cambridge Dictionary (opens in a new tab)Cambridge Dictionary · UK mould entry covering growth, shape/container, and related senses