diff --git a/Conversions/TemperatureConversions.php b/Conversions/TemperatureConversions.php
new file mode 100644
index 00000000..1be1fb52
--- /dev/null
+++ b/Conversions/TemperatureConversions.php
@@ -0,0 +1,115 @@
+<?php
+
+/**
+* This function converts the submitted
+* temperature (Celsius) and converts it into
+* Fahrenheit.
+*
+* @author Marco https://github.com/MaarcooC
+* @param float $celsius
+* @throws \Exception
+* @return float
+*/
+function CelsiusToFahrenheit($celsius)
+{
+    if (!is_numeric($celsius)) {
+        throw new \Exception("Temperature (Celsius) must be a number");
+    }
+
+    return round(($celsius * 9 / 5) + 32, 1);
+}
+
+/**
+* This function converts the submitted
+* temperature (Fahrenheit) and converts it into
+* Celsius.
+*
+* @author Marco https://github.com/MaarcooC
+* @param float $fahrenheit
+* @throws \Exception
+* @return float
+*/
+function FahrenheitToCelsius($fahrenheit)
+{
+    if (!is_numeric($fahrenheit)) {
+        throw new \Exception("Temperature (Fahrenheit) must be a number");
+    }
+
+    return round(($fahrenheit - 32) * 5 / 9, 1);
+}
+
+/**
+* This function converts the submitted
+* temperature (Celsius) and converts it into
+* Kelvin.
+*
+* @author Marco https://github.com/MaarcooC
+* @param float $celsius
+* @throws \Exception
+* @return float
+*/
+function CelsiusToKelvin($celsius)
+{
+    if (!is_numeric($celsius)) {
+        throw new \Exception("Temperature (Celsius) must be a number");
+    }
+
+    return round(($celsius + 273.15), 2);
+}
+
+/**
+* This function converts the submitted
+* temperature (Kelvin) and converts it into
+* Celsius.
+*
+* @author Marco https://github.com/MaarcooC
+* @param float $kelvin
+* @throws \Exception
+* @return float
+*/
+function KelvinToCelsius($kelvin)
+{
+    if (!is_numeric($kelvin)) {
+        throw new \Exception("Temperature (Kelvin) must be a number");
+    }
+
+    return round(($kelvin - 273.15), 2);
+}
+
+/**
+* This function converts the submitted
+* temperature (Kelvin) and converts it into
+* Fahrenheit.
+*
+* @author Marco https://github.com/MaarcooC
+* @param float $kelvin
+* @throws \Exception
+* @return float
+*/
+function KelvinToFahrenheit($kelvin)
+{
+    if (!is_numeric($kelvin)) {
+        throw new \Exception("Temperature (Kelvin) must be a number");
+    }
+
+    return round(($kelvin - 273.15) * 1.8 + 32, 2);
+}
+
+/**
+* This function converts the submitted
+* temperature (Fahrenheit) and converts it into
+* kelvin.
+*
+* @author Marco https://github.com/MaarcooC
+* @param float $fahrenheit
+* @throws \Exception
+* @return float
+*/
+function FahrenheitToKelvin($fahrenheit)
+{
+    if (!is_numeric($fahrenheit)) {
+        throw new \Exception("Temperature (Fahrenheit) must be a number");
+    }
+
+    return round(($fahrenheit - 32) * 5 / 9 + 273.15, 2);
+}
diff --git a/DIRECTORY.md b/DIRECTORY.md
index 861f2d22..30aa2c7f 100644
--- a/DIRECTORY.md
+++ b/DIRECTORY.md
@@ -15,6 +15,7 @@
   * [Hexadecimaltodecimal](./Conversions/HexadecimalToDecimal.php)
   * [Octaltodecimal](./Conversions/OctalToDecimal.php)
   * [Speedconversion](./Conversions/SpeedConversion.php)
+  * [Temperatureconversions](./Conversions/TemperatureConversions.php)
 
 ## Datastructures
   * Avltree
@@ -70,6 +71,7 @@
   * [Median](./Maths/Median.php)
   * [Mode](./Maths/Mode.php)
   * [Neonnumber](./Maths/NeonNumber.php)
+  * [Perfectnumber](./Maths/PerfectNumber.php)
   * [Perfectsquare](./Maths/PerfectSquare.php)
   * Projecteuler
     * [Problem1](./Maths/ProjectEuler/Problem1.php)
diff --git a/Maths/PerfectNumber.php b/Maths/PerfectNumber.php
new file mode 100644
index 00000000..5d7112e6
--- /dev/null
+++ b/Maths/PerfectNumber.php
@@ -0,0 +1,39 @@
+<?php
+
+/**
+This function returns true
+* if the submitted number is perfect,
+* false if it is not.
+*
+* A perfect number is a positive integer that is
+* equal to the sum of its positive proper
+* divisors, excluding the number itself.
+*
+* About perfect numbers: https://en.wikipedia.org/wiki/Perfect_number
+*
+* @author Marco https://github.com/MaarcooC
+* @param int $number
+* @return bool
+*/
+function perfect_number($number)
+{
+    /*Input validation*/
+    if (!is_int($number) || $number <= 1) {
+        /*Return false for non-integer or non-positive numbers*/
+        return false;
+    }
+
+    $divisorsSum = 1; /*1 is a common divisor for every number*/
+
+    /*Check for divisors up to the square root of the number*/
+    for ($i = 2; $i * $i <= $number; $i++) {
+        if ($number % $i == 0) {
+            $divisorsSum += $i; /*add i to the sum of divisors*/
+            if ($i != $number / $i) { /*add the complement divisor*/
+                $divisorsSum += $number / $i;
+            }
+        }
+    }
+
+    return $divisorsSum == $number;
+}
diff --git a/tests/Conversions/ConversionsTest.php b/tests/Conversions/ConversionsTest.php
index 8280a2fd..93893b4e 100644
--- a/tests/Conversions/ConversionsTest.php
+++ b/tests/Conversions/ConversionsTest.php
@@ -9,6 +9,7 @@
 require_once __DIR__ . '/../../Conversions/OctalToDecimal.php';
 require_once __DIR__ . '/../../Conversions/HexadecimalToDecimal.php';
 require_once __DIR__ . '/../../Conversions/SpeedConversion.php';
+require_once __DIR__ . '/../../Conversions/TemperatureConversions.php';
 
 class ConversionsTest extends TestCase
 {
@@ -85,4 +86,60 @@ public function testSpeedConversion()
         $this->expectException(\Exception::class);
         convertSpeed(1, 'km/h', 'miles');
     }
+
+    public function testCelsiusToFahrenheit()
+    {
+        $this->assertEquals(32.0, CelsiusToFahrenheit(0));
+        $this->assertEquals(212.0, CelsiusToFahrenheit(100));
+        $this->assertEquals(98.6, CelsiusToFahrenheit(37));
+        $this->expectException(\Exception::class);
+        $this->expectExceptionMessage('Temperature (Celsius) must be a number');
+        CelsiusToFahrenheit("non-numeric");
+    }
+
+    public function testFahrenheitToCelsius()
+    {
+        $this->assertEquals(0.0, FahrenheitToCelsius(32));
+        $this->assertEquals(100.0, FahrenheitToCelsius(212));
+        $this->assertEquals(37.0, FahrenheitToCelsius(98.6));
+        $this->expectException(\Exception::class);
+        $this->expectExceptionMessage('Temperature (Fahrenheit) must be a number');
+        FahrenheitToCelsius("non-numeric");
+    }
+
+    public function testCelsiusToKelvin()
+    {
+        $this->assertEquals(273.15, CelsiusToKelvin(0));
+        $this->assertEquals(373.15, CelsiusToKelvin(100));
+        $this->expectException(\Exception::class);
+        $this->expectExceptionMessage('Temperature (Celsius) must be a number');
+        CelsiusToKelvin("non-numeric");
+    }
+
+    public function testKelvinToCelsius()
+    {
+        $this->assertEquals(0.0, KelvinToCelsius(273.15));
+        $this->assertEquals(100.0, KelvinToCelsius(373.15));
+        $this->expectException(\Exception::class);
+        $this->expectExceptionMessage('Temperature (Kelvin) must be a number');
+        KelvinToCelsius("non-numeric");
+    }
+
+    public function testKelvinToFahrenheit()
+    {
+        $this->assertEquals(32.0, KelvinToFahrenheit(273.15));
+        $this->assertEquals(212.0, KelvinToFahrenheit(373.15));
+        $this->expectException(\Exception::class);
+        $this->expectExceptionMessage('Temperature (Kelvin) must be a number');
+        KelvinToFahrenheit("non-numeric");
+    }
+
+    public function testFahrenheitToKelvin()
+    {
+        $this->assertEquals(273.15, FahrenheitToKelvin(32));
+        $this->assertEquals(373.15, FahrenheitToKelvin(212));
+        $this->expectException(\Exception::class);
+        $this->expectExceptionMessage('Temperature (Fahrenheit) must be a number');
+        FahrenheitToKelvin("non-numeric");
+    }
 }
diff --git a/tests/Maths/MathsTest.php b/tests/Maths/MathsTest.php
index 66a86347..a9428b7f 100644
--- a/tests/Maths/MathsTest.php
+++ b/tests/Maths/MathsTest.php
@@ -22,6 +22,7 @@
 require_once __DIR__ . '/../../Maths/Mode.php';
 require_once __DIR__ . '/../../Maths/FastInverseSquareRoot.php';
 require_once __DIR__ . '/../../Maths/BaseX.php';
+require_once __DIR__ . '/../../Maths/PerfectNumber.php';
 
 class MathsTest extends TestCase
 {
@@ -185,6 +186,22 @@ public function testGreatestCommonDivisor()
         $this->assertEquals(3, gcd(9, 12));
     }
 
+    public function testPerfectNumber()
+    {
+        $this->assertTrue(perfect_number(6));
+        $this->assertTrue(perfect_number(28));
+        $this->assertTrue(perfect_number(496));
+
+        $this->assertFalse(perfect_number(10));
+        $this->assertFalse(perfect_number(15));
+
+        $this->assertFalse(perfect_number(-6));
+        $this->assertFalse(perfect_number(0));
+        $this->assertFalse(perfect_number(1));
+        $this->assertFalse(perfect_number(2.5));
+        $this->assertFalse(perfect_number("string"));
+    }
+
     public function testFastInverseSquareRoot()
     {
         $this->assertEqualsWithDelta(0.31568579235273, fastInvSqrt(10), 0.00001);