diff --git a/library/core/src/num/f128.rs b/library/core/src/num/f128.rs
index cc142fab8e821..4630fd729c6a1 100644
--- a/library/core/src/num/f128.rs
+++ b/library/core/src/num/f128.rs
@@ -108,6 +108,17 @@ pub mod consts {
     pub const FRAC_1_SQRT_3: f128 =
         0.577350269189625764509148780501957455647601751270126876018602_f128;
 
+    /// sqrt(5)
+    #[unstable(feature = "more_float_constants", issue = "146939")]
+    // Also, #[unstable(feature = "f128", issue = "116909")]
+    pub const SQRT_5: f128 = 2.23606797749978969640917366873127623544061835961152572427089_f128;
+
+    /// 1/sqrt(5)
+    #[unstable(feature = "more_float_constants", issue = "146939")]
+    // Also, #[unstable(feature = "f128", issue = "116909")]
+    pub const FRAC_1_SQRT_5: f128 =
+        0.447213595499957939281834733746255247088123671922305144854179_f128;
+
     /// Euler's number (e)
     #[unstable(feature = "f128", issue = "116909")]
     pub const E: f128 = 2.71828182845904523536028747135266249775724709369995957496697_f128;
diff --git a/library/core/src/num/f16.rs b/library/core/src/num/f16.rs
index e97a44e991f66..21ba8f1f2828d 100644
--- a/library/core/src/num/f16.rs
+++ b/library/core/src/num/f16.rs
@@ -103,6 +103,16 @@ pub mod consts {
     // Also, #[unstable(feature = "more_float_constants", issue = "146939")]
     pub const FRAC_1_SQRT_3: f16 = 0.577350269189625764509148780501957456_f16;
 
+    /// sqrt(5)
+    #[unstable(feature = "more_float_constants", issue = "146939")]
+    // Also, #[unstable(feature = "f16", issue = "116909")]
+    pub const SQRT_5: f16 = 2.23606797749978969640917366873127623_f16;
+
+    /// 1/sqrt(5)
+    #[unstable(feature = "more_float_constants", issue = "146939")]
+    // Also, #[unstable(feature = "f16", issue = "116909")]
+    pub const FRAC_1_SQRT_5: f16 = 0.44721359549995793928183473374625524_f16;
+
     /// Euler's number (e)
     #[unstable(feature = "f16", issue = "116909")]
     pub const E: f16 = 2.71828182845904523536028747135266250_f16;
diff --git a/library/core/src/num/f32.rs b/library/core/src/num/f32.rs
index 3d8249631037f..c4ec774f5956f 100644
--- a/library/core/src/num/f32.rs
+++ b/library/core/src/num/f32.rs
@@ -356,6 +356,14 @@ pub mod consts {
     #[unstable(feature = "more_float_constants", issue = "146939")]
     pub const FRAC_1_SQRT_3: f32 = 0.577350269189625764509148780501957456_f32;
 
+    /// sqrt(5)
+    #[unstable(feature = "more_float_constants", issue = "146939")]
+    pub const SQRT_5: f32 = 2.23606797749978969640917366873127623_f32;
+
+    /// 1/sqrt(5)
+    #[unstable(feature = "more_float_constants", issue = "146939")]
+    pub const FRAC_1_SQRT_5: f32 = 0.44721359549995793928183473374625524_f32;
+
     /// Euler's number (e)
     #[stable(feature = "rust1", since = "1.0.0")]
     pub const E: f32 = 2.71828182845904523536028747135266250_f32;
diff --git a/library/core/src/num/f64.rs b/library/core/src/num/f64.rs
index 566a6a7ec947f..0bb8813235779 100644
--- a/library/core/src/num/f64.rs
+++ b/library/core/src/num/f64.rs
@@ -356,6 +356,14 @@ pub mod consts {
     #[unstable(feature = "more_float_constants", issue = "146939")]
     pub const FRAC_1_SQRT_3: f64 = 0.577350269189625764509148780501957456_f64;
 
+    /// sqrt(5)
+    #[unstable(feature = "more_float_constants", issue = "146939")]
+    pub const SQRT_5: f64 = 2.23606797749978969640917366873127623_f64;
+
+    /// 1/sqrt(5)
+    #[unstable(feature = "more_float_constants", issue = "146939")]
+    pub const FRAC_1_SQRT_5: f64 = 0.44721359549995793928183473374625524_f64;
+
     /// Euler's number (e)
     #[stable(feature = "rust1", since = "1.0.0")]
     pub const E: f64 = 2.71828182845904523536028747135266250_f64;