diff --git a/src/MDUnitsSet.php b/src/MDUnitsSet.php
index bd162c6..903d033 100644
--- a/src/MDUnitsSet.php
+++ b/src/MDUnitsSet.php
@@ -14,6 +14,64 @@ final class MDUnitsSet extends MDValueSet {
     const UNITS_LENGTH = ['', 'm', 'dm', 'cm', 'mm'];
     const UNITS_WEIGHT = ['', 't', 'kg', 'g'];
 
+    const UNITS_LENGTH_TO_MICROMETER = [
+        'm'  => 1000000,
+        'dm' => 100000,
+        'cm' => 10000,
+        'mm' => 1000,
+    ];
+
+    const UNITS_WEIGHT_TO_MILLIGRAMM = [
+        'm'  => 1000000,
+        'dm' => 100000,
+        'cm' => 10000,
+        'mm' => 1000,
+    ];
+
+    /**
+     * Converts a given length to micrometers.
+     *
+     * @param mixed  $value Input value to convert.
+     * @param string $unit  Length unit of the value to convert.
+     *
+     * @return float|null
+     */
+    public static function convertLengthToMicrometer(mixed $value, string $unit):float|null {
+
+        if (!isset(self::UNITS_LENGTH_TO_MICROMETER[$unit])) return null;
+
+        try {
+            $number = MD_STD_IN::sanitize_float($value);
+            return floatval($number * self::UNITS_LENGTH_TO_MICROMETER[$unit]);
+        }
+        catch (MDgenericInvalidInputsException $e) {
+            return null;
+        }
+
+    }
+
+    /**
+     * Converts a given length to micrometers.
+     *
+     * @param mixed  $value Input value to convert.
+     * @param string $unit  Weight unit of the value to convert.
+     *
+     * @return float|null
+     */
+    public static function convertWeightToMilligramm(mixed $value, string $unit):float|null {
+
+        if (!isset(self::UNITS_WEIGHT_TO_MILLIGRAMM[$unit])) return null;
+
+        try {
+            $number = MD_STD_IN::sanitize_float($value);
+            return floatval($number * self::UNITS_WEIGHT_TO_MILLIGRAMM[$unit]);
+        }
+        catch (MDgenericInvalidInputsException $e) {
+            return null;
+        }
+
+    }
+
     /**
      * Returns a translated list of length units.
      *