diff --git a/Math/Topology/Metrics2D.php b/Math/Topology/Metrics2D.php
index 709ccefb3..d047f3653 100644
--- a/Math/Topology/Metrics2D.php
+++ b/Math/Topology/Metrics2D.php
@@ -75,7 +75,7 @@ final class Metrics2D
     }
 
     /**
-     * Euclidean metric.
+     * Octile metric.
      *
      * @latex d(p, q) = \begin{cases}(\sqrt{2} - 1) \times |p_i - q_i| + |p_{i+1} - q_{i+1}|,& \text{if } |p_i - q_i| < |p_{i+1} - q_{i+1}|\\(\sqrt{2} - 1) \times |p_{i+1} - q_{i+1}| + |p_i - q_i|,&\text{if } |p_i - q_i| \geq |p_{i+1} - q_{i+1}|\end{cases}
      *
@@ -188,7 +188,7 @@ final class Metrics2D
      */
     public static function angularSeparation(array $a, array $b) : float
     {
-        return ($a['x'] * $b['x'] + $a['y'] * $b['y']) / pow(($a['x'] ** 2 + $a['y'] ** 2) * ($b['x'] ** 2 + $b['y'] ** 2), 1 / 2);
+        return ($a['x'] * $b['x'] + $a['y'] * $b['y']) / \pow(($a['x'] ** 2 + $a['y'] ** 2) * ($b['x'] ** 2 + $b['y'] ** 2), 1 / 2);
     }
 
     /**
diff --git a/Math/Topology/MetricsND.php b/Math/Topology/MetricsND.php
new file mode 100644
index 000000000..7f03af3f4
--- /dev/null
+++ b/Math/Topology/MetricsND.php
@@ -0,0 +1,256 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   phpOMS\Math\Topology
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+
+declare(strict_types=1);
+
+namespace phpOMS\Math\Topology;
+
+use phpOMS\Math\Matrix\Exception\InvalidDimensionException;
+
+/**
+ * Metrics.
+ *
+ * @package phpOMS\Math\Topology
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+final class MetricsND
+{
+    /**
+     * Constructor
+     *
+     * @since 1.0.0
+     * @codeCoverageIgnore
+     */
+    private function __construct()
+    {
+    }
+
+    /**
+     * Manhatten metric.
+     *
+     * @latex d(p, q) = \sum_{n=1}^N{|p_i - q_i|}
+     *
+     * @param array $a n-D array
+     * @param array $b n-D array
+     *
+     * @return float
+     *
+     * @since 1.0.0
+     */
+    public static function manhattan(array $a, array $b) : float
+    {
+        if (\count($a) !== \count($b)) {
+            throw new InvalidDimensionException(\count($a) . 'x' . \count($b));
+        }
+
+        $dist = 0.0;
+        foreach ($a as $key => $e) {
+            $dist += \abs($a[$key] - $b[$key]);
+        }
+
+        return $dist;
+    }
+
+    /**
+     * Euclidean metric.
+     *
+     * @latex d(p, q) = \sqrt{\sum_{n=1}^N{(p_i - q_i)^2}}
+     *
+     * @param array $a n-D array
+     * @param array $b n-D array
+     *
+     * @return float
+     *
+     * @since 1.0.0
+     */
+    public static function euclidean(array $a, array $b) : float
+    {
+        if (\count($a) !== \count($b)) {
+            throw new InvalidDimensionException(\count($a) . 'x' . \count($b));
+        }
+
+        $dist = 0.0;
+        foreach ($a as $key => $e) {
+            $dist += \abs($a[$key] - $b[$key]) ** 2;
+        }
+
+        return \sqrt($dist);
+    }
+
+    /**
+     * Chebyshev metric.
+     *
+     * @latex d(p, q) = \max_i{(|p_i - q_i|)}
+     *
+     * @param array $a n-D array
+     * @param array $b n-D array
+     *
+     * @return float
+     *
+     * @since 1.0.0
+     */
+    public static function chebyshev(array $a, array $b) : float
+    {
+        if (\count($a) !== \count($b)) {
+            throw new InvalidDimensionException(\count($a) . 'x' . \count($b));
+        }
+
+        $dist = [];
+        foreach ($a as $key => $e) {
+            $dist[] = \abs($a[$key] - $b[$key]);
+        }
+
+        return \max($dist);
+    }
+
+    /**
+     * Minkowski metric.
+     *
+     * @latex d(p, q) = \sqrt[\lambda]{\sum_{n=1}^N{|p_i - q_i|^\lambda}}
+     *
+     * @param array $a      n-D array
+     * @param array $b      n-D array
+     * @param int   $lambda Lambda
+     *
+     * @return float
+     *
+     * @since 1.0.0
+     */
+    public static function minkowski(array $a, array $b, int $lambda) : float
+    {
+        if (\count($a) !== \count($b)) {
+            throw new InvalidDimensionException(\count($a) . 'x' . \count($b));
+        }
+
+        $dist = 0.0;
+        foreach ($a as $key => $e) {
+            $dist += \pow(\abs($a[$key] - $b[$key]), $lambda);
+        }
+
+        return \pow($dist, 1 / $lambda);
+    }
+
+    /**
+     * Canberra metric.
+     *
+     * @latex d(p, q) = \sum_{n=1}^N{\frac{|p_i - q_i|}{|p_i| + |q_i|}
+     *
+     * @param array $a n-D array
+     * @param array $b n-D array
+     *
+     * @return float
+     *
+     * @since 1.0.0
+     */
+    public static function canberra(array $a, array $b) : float
+    {
+        if (\count($a) !== \count($b)) {
+            throw new InvalidDimensionException(\count($a) . 'x' . \count($b));
+        }
+
+        $dist = 0.0;
+        foreach ($a as $key => $e) {
+            $dist += \abs($a[$key] - $b[$key]) / (\abs($a[$key]) + \abs($b[$key]));
+        }
+
+        return $dist;
+    }
+
+    /**
+     * Bray Curtis metric.
+     *
+     * @latex d(p, q) = \frac{\sum_{n=1}^N{|p_i - q_i|}}{\sum_{n=1}^N{(p_i + q_i)}}
+     *
+     * @param array $a n-D array
+     * @param array $b n-D array
+     *
+     * @return float
+     *
+     * @since 1.0.0
+     */
+    public static function brayCurtis(array $a, array $b) : float
+    {
+        if (\count($a) !== \count($b)) {
+            throw new InvalidDimensionException(\count($a) . 'x' . \count($b));
+        }
+
+        $distTop    = 0.0;
+        $distBottom = 0.0;
+        foreach ($a as $key => $e) {
+            $distTop    += \abs($a[$key] - $b[$key]);
+            $distBottom += $a[$key] + $b[$key];
+        }
+
+        return $distTop / $distBottom;
+    }
+
+    /**
+     * Angular separation metric.
+     *
+     * @latex d(p, q) = \frac{\sum_{n=1}^N{p_i * q_i}}{\left(\sum_{n=1}^N{p_i^2} * \sum_{n=1}^N{q_i^2}\right)^\frac{1}{2}}
+     *
+     * @param array $a n-D array
+     * @param array $b n-D array
+     *
+     * @return float
+     *
+     * @since 1.0.0
+     */
+    public static function angularSeparation(array $a, array $b) : float
+    {
+        if (\count($a) !== \count($b)) {
+            throw new InvalidDimensionException(\count($a) . 'x' . \count($b));
+        }
+
+        $distTop     = 0.0;
+        $distBottomA = 0.0;
+        $distBottomB = 0.0;
+        foreach ($a as $key => $e) {
+            $distTop     += $a[$key] * $b[$key];
+            $distBottomA += $a[$key] ** 2;
+            $distBottomB += $b[$key] ** 2;
+        }
+
+        return $distTop / \pow($distBottomA * $distBottomB, 1 / 2);
+    }
+
+    /**
+     * Hamming metric.
+     *
+     * @latex d(p, q) = \sum_{n=1}^N{|p_i - q_i|}
+     *
+     * @param array $a n-D array
+     * @param array $b n-D array
+     *
+     * @return int
+     *
+     * @since 1.0.0
+     */
+    public static function hamming(array $a, array $b) : int
+    {
+        if (($size = \count($a)) !== \count($b)) {
+            throw new InvalidDimensionException(\count($a) . 'x' . \count($b));
+        }
+
+        $dist = 0;
+        for ($i = 0; $i < $size; ++$i) {
+            if ($a[$i] !== $b[$i]) {
+                ++$dist;
+            }
+        }
+
+        return $dist;
+    }
+}
diff --git a/tests/Math/Topology/MetricsNDTest.php b/tests/Math/Topology/MetricsNDTest.php
new file mode 100644
index 000000000..4eaf779d0
--- /dev/null
+++ b/tests/Math/Topology/MetricsNDTest.php
@@ -0,0 +1,147 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   tests
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace phpOMS\tests\Math\Number;
+
+use phpOMS\Math\Topology\Metrics2D;
+use phpOMS\Math\Topology\MetricsND;
+
+/**
+ * @testdox phpOMS\tests\Math\Topology\MetricsNDTest: Metric/distance calculations
+ *
+ * @internal
+ */
+class MetricsNDTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @testdox The manhattan distance can be calculated
+     * @covers phpOMS\Math\Topology\MetricsND
+     * @group framework
+     */
+    public function testManhattan() : void
+    {
+        self::assertEquals(
+            MetricsND::manhattan(['x' => 0, 'y' => 3], ['x' => 7, 'y' => 6]),
+            MetricsND::manhattan(['x' => 0, 'y' => 3], ['x' => 7, 'y' => 6])
+        );
+    }
+
+    /**
+     * @testdox The euclidean distance can be calculated
+     * @covers phpOMS\Math\Topology\MetricsND
+     * @group framework
+     */
+    public function testEuclidean() : void
+    {
+        self::assertEqualsWithDelta(
+            Metrics2D::euclidean(['x' => 0, 'y' => 3], ['x' => 7, 'y' => 6]),
+            MetricsND::euclidean(['x' => 0, 'y' => 3], ['x' => 7, 'y' => 6]),
+            0.1
+        );
+    }
+
+    /**
+     * @testdox The chebyshev distance can be calculated
+     * @covers phpOMS\Math\Topology\MetricsND
+     * @group framework
+     */
+    public function testChebyshev() : void
+    {
+        self::assertEquals(
+            MetricsND::chebyshev(['x' => 0, 'y' => 3], ['x' => 7, 'y' => 6]),
+            MetricsND::chebyshev(['x' => 0, 'y' => 3], ['x' => 7, 'y' => 6])
+        );
+    }
+
+    /**
+     * @testdox The minkowski distance can be calculated
+     * @covers phpOMS\Math\Topology\MetricsND
+     * @group framework
+     */
+    public function testMinkowski() : void
+    {
+        self::assertEqualsWithDelta(
+            Metrics2D::minkowski(['x' => 0, 'y' => 3], ['x' => 7, 'y' => 6], 3),
+            MetricsND::minkowski(['x' => 0, 'y' => 3], ['x' => 7, 'y' => 6], 3),
+            0.1
+        );
+    }
+
+    /**
+     * @testdox The canberra distance can be calculated
+     * @covers phpOMS\Math\Topology\MetricsND
+     * @group framework
+     */
+    public function testCanberra() : void
+    {
+        self::assertEqualsWithDelta(
+            Metrics2D::canberra(['x' => 0, 'y' => 3], ['x' => 7, 'y' => 6]),
+            MetricsND::canberra(['x' => 0, 'y' => 3], ['x' => 7, 'y' => 6]),
+            0.1
+        );
+    }
+
+    /**
+     * @testdox The bray-curtis distance can be calculated
+     * @covers phpOMS\Math\Topology\MetricsND
+     * @group framework
+     */
+    public function testBrayCurtis() : void
+    {
+        self::assertEqualsWithDelta(
+            Metrics2D::brayCurtis(['x' => 0, 'y' => 3], ['x' => 7, 'y' => 6]),
+            MetricsND::brayCurtis(['x' => 0, 'y' => 3], ['x' => 7, 'y' => 6]),
+            0.1
+        );
+    }
+
+    /**
+     * @testdox The angular distance can be calculated
+     * @covers phpOMS\Math\Topology\MetricsND
+     * @group framework
+     */
+    public function testAngularSeparation() : void
+    {
+        self::assertEqualsWithDelta(
+            Metrics2D::angularSeparation(['x' => 0, 'y' => 3], ['x' => 7, 'y' => 6]),
+            MetricsND::angularSeparation(['x' => 0, 'y' => 3], ['x' => 7, 'y' => 6]),
+            0.1
+        );
+    }
+
+    /**
+     * @testdox The hamming distance can be calculated
+     * @covers phpOMS\Math\Topology\MetricsND
+     * @group framework
+     */
+    public function testHammingDistance() : void
+    {
+        self::assertEquals(
+            MetricsND::hamming([1, 1, 1, 1], [0, 1, 0, 0]),
+            MetricsND::hamming([1, 1, 1, 1], [0, 1, 0, 0]),
+        );
+    }
+
+    /**
+     * @testdox Different dimension sizes for the coordinates in the hamming metric throw a InvalidDimensionException
+     * @covers phpOMS\Math\Topology\MetricsND
+     * @group framework
+     */
+    public function testInvalidHammingDimension() : void
+    {
+        self::expectException(\phpOMS\Math\Matrix\Exception\InvalidDimensionException::class);
+
+        Metrics2D::ulam([3, 6, 4], [4, 6, 8, 3]);
+    }
+}