diff --git a/packages/mui-base/src/NumberField/utils/parse.ts b/packages/mui-base/src/NumberField/utils/parse.ts
index b74594c0a..8f400efdd 100644
--- a/packages/mui-base/src/NumberField/utils/parse.ts
+++ b/packages/mui-base/src/NumberField/utils/parse.ts
@@ -32,13 +32,10 @@ export function getNumberLocaleDetails(
 }
 
 export function parseNumber(formattedNumber: string, options?: Intl.NumberFormatOptions) {
-  const isArabic = formattedNumber.match(ARABIC_RE);
-  const isHan = formattedNumber.match(HAN_RE);
-
   let locale: string | undefined;
-  if (isArabic) {
+  if (ARABIC_RE.test(formattedNumber)) {
     locale = 'ar';
-  } else if (isHan) {
+  } else if (HAN_RE.test(formattedNumber)) {
     locale = 'zh';
   }
 
diff --git a/packages/mui-base/src/NumberField/utils/validate.ts b/packages/mui-base/src/NumberField/utils/validate.ts
index dbd23663d..cceeb3418 100644
--- a/packages/mui-base/src/NumberField/utils/validate.ts
+++ b/packages/mui-base/src/NumberField/utils/validate.ts
@@ -3,7 +3,7 @@ import { getFormatter } from './format';
 
 export function removeFloatingPointErrors(value: number, format: Intl.NumberFormatOptions = {}) {
   return parseFloat(
-    getFormatter(undefined, {
+    getFormatter('en-US', {
       maximumFractionDigits: format.maximumFractionDigits,
       minimumFractionDigits: format.minimumFractionDigits,
       useGrouping: false,