diff --git a/packages/block-editor/src/components/aspect-ratio-dropdown/index.js b/packages/block-editor/src/components/aspect-ratio-dropdown/index.js
index c7dbc6da302f23..fc4692b545fda3 100644
--- a/packages/block-editor/src/components/aspect-ratio-dropdown/index.js
+++ b/packages/block-editor/src/components/aspect-ratio-dropdown/index.js
@@ -39,7 +39,7 @@ function AspectRatioGroup( {
 	);
 }
 
-function ratioToNumber( str ) {
+export function ratioToNumber( str ) {
 	// TODO: support two-value aspect ratio?
 	// https://css-tricks.com/almanac/properties/a/aspect-ratio/#aa-it-can-take-two-values
 	const [ a, b, ...rest ] = str.split( '/' ).map( Number );
diff --git a/packages/block-editor/src/components/aspect-ratio-dropdown/test/index.js b/packages/block-editor/src/components/aspect-ratio-dropdown/test/index.js
new file mode 100644
index 00000000000000..28763a6f66093c
--- /dev/null
+++ b/packages/block-editor/src/components/aspect-ratio-dropdown/test/index.js
@@ -0,0 +1,22 @@
+/**
+ * Internal dependencies
+ */
+import { ratioToNumber } from '../';
+
+test( 'ratioToNumber', () => {
+	expect( ratioToNumber( '1/1' ) ).toBe( 1 );
+	expect( ratioToNumber( '1' ) ).toBe( 1 );
+	expect( ratioToNumber( '11/11' ) ).toBe( 1 );
+	expect( ratioToNumber( '16/9' ) ).toBe( 16 / 9 );
+	expect( ratioToNumber( '4/3' ) ).toBe( 4 / 3 );
+	expect( ratioToNumber( '3/2' ) ).toBe( 3 / 2 );
+	expect( ratioToNumber( '2/1' ) ).toBe( 2 );
+	expect( ratioToNumber( '1/2' ) ).toBe( 1 / 2 );
+	expect( ratioToNumber( '2/3' ) ).toBe( 2 / 3 );
+	expect( ratioToNumber( '3/4' ) ).toBe( 3 / 4 );
+	expect( ratioToNumber( '9/16' ) ).toBe( 9 / 16 );
+	expect( ratioToNumber( '1/16' ) ).toBe( 1 / 16 );
+	expect( ratioToNumber( '16/1' ) ).toBe( 16 );
+	expect( ratioToNumber( '1/9' ) ).toBe( 1 / 9 );
+	expect( ratioToNumber( 'auto' ) ).toBe( NaN );
+} );