diff --git a/CHANGELOG.md b/CHANGELOG.md
index bb7703b..7e1719f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,12 @@
-## [4.8.0](https://github.com/shivam091/unit_measurements/compare/v4.7.0...v4.8.0) - 2023-10-11
+## [4.9.0](https://github.com/shivam091/unit_measurements/compare/v4.8.0...v4.9.0) - 2023-10-13
+
+### What's new
+
+- Added units group for `information entropy` units.
+
+----------
+
+## [4.8.0](https://github.com/shivam091/unit_measurements/compare/v4.7.0...v4.8.0) - 2023-10-12
 
 ### What's new
 
diff --git a/Gemfile.lock b/Gemfile.lock
index ca6630c..0c4587e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    unit_measurements (4.8.0)
+    unit_measurements (4.9.0)
       activesupport (~> 7.0)
 
 GEM
diff --git a/lib/unit_measurements/unit_groups/all.rb b/lib/unit_measurements/unit_groups/all.rb
index 279cd4d..b78e924 100644
--- a/lib/unit_measurements/unit_groups/all.rb
+++ b/lib/unit_measurements/unit_groups/all.rb
@@ -50,6 +50,7 @@
 require_relative "radiation_exposure"
 require_relative "radiation_absorbed_dose"
 require_relative "radiation_equivalent_dose"
+require_relative "information_entropy"
 
 ## Other units
 
diff --git a/lib/unit_measurements/unit_groups/information_entropy.rb b/lib/unit_measurements/unit_groups/information_entropy.rb
new file mode 100644
index 0000000..687634f
--- /dev/null
+++ b/lib/unit_measurements/unit_groups/information_entropy.rb
@@ -0,0 +1,15 @@
+# -*- encoding: utf-8 -*-
+# -*- frozen_string_literal: true -*-
+# -*- warn_indent: true -*-
+
+UnitMeasurements::InformationEntropy = UnitMeasurements.build do
+  primitive "nat"
+
+  si_unit "b", value: "1 Sh", aliases: ["bit", "bits"]
+  si_unit "B", value: [2.pow(3), "b"], aliases: ["byte", "bytes"]
+
+  unit "Sh", value: [Math.log(2), "nat"], aliases: ["shannon", "shannons"]
+  unit "nat", aliases: ["nit", "nepit", "natural unit of information"]
+  unit "nybl", value: [2.pow(2), "b"], aliases: ["nibble", "nibbles", "nybble", "nyble"]
+  unit "Hart", value: [Math.log(10), "nat"], aliases: ["hartley", "ban", "dit"]
+end
diff --git a/lib/unit_measurements/version.rb b/lib/unit_measurements/version.rb
index cb2370c..3bf3a77 100644
--- a/lib/unit_measurements/version.rb
+++ b/lib/unit_measurements/version.rb
@@ -3,5 +3,5 @@
 # -*- warn_indent: true -*-
 
 module UnitMeasurements
-  VERSION = "4.8.0"
+  VERSION = "4.9.0"
 end
diff --git a/spec/unit_measurements/unit_groups/information_entropy_spec.rb b/spec/unit_measurements/unit_groups/information_entropy_spec.rb
new file mode 100644
index 0000000..21ff232
--- /dev/null
+++ b/spec/unit_measurements/unit_groups/information_entropy_spec.rb
@@ -0,0 +1,151 @@
+# -*- encoding: utf-8 -*-
+# -*- frozen_string_literal: true -*-
+# -*- warn_indent: true -*-
+
+# spec/unit_measurements/unit_groups/information_entropy_spec.rb
+
+RSpec.describe UnitMeasurements::InformationEntropy do
+  describe "nat" do
+    subject { described_class.new(1, "nat") }
+
+    it "converts to Sh" do
+      expect(subject.convert_to("Sh").quantity).to eq(1.44269504088896)
+    end
+
+    it "converts to Hart" do
+      expect(subject.convert_to("Hart").quantity).to eq(0.434294481903252)
+    end
+
+    it "converts to b" do
+      expect(subject.convert_to("b").quantity).to eq(1.44269504088896)
+    end
+
+    it "converts to B" do
+      expect(subject.convert_to("B").quantity).to eq(0.18033688011112)
+    end
+
+    it "converts to nybl" do
+      expect(subject.convert_to("nybl").quantity).to eq(0.360673760222241)
+    end
+  end
+
+  describe "Sh" do
+    subject { described_class.new(1, "Sh") }
+
+    it "converts to nat" do
+      expect(subject.convert_to("nat").quantity).to eq(0.693147180559945)
+    end
+
+    it "converts to Hart" do
+      expect(subject.convert_to("Hart").quantity).to eq(0.301029995663981)
+    end
+
+    it "converts to b" do
+      expect(subject.convert_to("b").quantity).to eq(1)
+    end
+
+    it "converts to B" do
+      expect(subject.convert_to("B").quantity).to eq(0.125)
+    end
+
+    it "converts to nybl" do
+      expect(subject.convert_to("nybl").quantity).to eq(0.25)
+    end
+  end
+
+  describe "Hart" do
+    subject { described_class.new(1, "Hart") }
+
+    it "converts to nat" do
+      expect(subject.convert_to("nat").quantity).to eq(2.30258509299405)
+    end
+
+    it "converts to Sh" do
+      expect(subject.convert_to("Sh").quantity).to eq(3.32192809488736)
+    end
+
+    it "converts to b" do
+      expect(subject.convert_to("b").quantity).to eq(3.32192809488736)
+    end
+
+    it "converts to B" do
+      expect(subject.convert_to("B").quantity).to eq(0.41524101186092)
+    end
+
+    it "converts to nybl" do
+      expect(subject.convert_to("nybl").quantity).to eq(0.830482023721841)
+    end
+  end
+
+  describe "b" do
+    subject { described_class.new(1, "b") }
+
+    it "converts to nat" do
+      expect(subject.convert_to("nat").quantity).to eq(0.693147180559945)
+    end
+
+    it "converts to Sh" do
+      expect(subject.convert_to("Sh").quantity).to eq(1)
+    end
+
+    it "converts to Hart" do
+      expect(subject.convert_to("Hart").quantity).to eq(0.301029995663981)
+    end
+
+    it "converts to B" do
+      expect(subject.convert_to("B").quantity).to eq(0.125)
+    end
+
+    it "converts to nybl" do
+      expect(subject.convert_to("nybl").quantity).to eq(0.25)
+    end
+  end
+
+  describe "B" do
+    subject { described_class.new(1, "B") }
+
+    it "converts to nat" do
+      expect(subject.convert_to("nat").quantity).to eq(5.54517744447956)
+    end
+
+    it "converts to Sh" do
+      expect(subject.convert_to("Sh").quantity).to eq(8)
+    end
+
+    it "converts to Hart" do
+      expect(subject.convert_to("Hart").quantity).to eq(2.40823996531185)
+    end
+
+    it "converts to b" do
+      expect(subject.convert_to("b").quantity).to eq(8)
+    end
+
+    it "converts to nybl" do
+      expect(subject.convert_to("nybl").quantity).to eq(2)
+    end
+  end
+
+  describe "nybl" do
+    subject { described_class.new(1, "nybl") }
+
+    it "converts to nat" do
+      expect(subject.convert_to("nat").quantity).to eq(2.77258872223978)
+    end
+
+    it "converts to Sh" do
+      expect(subject.convert_to("Sh").quantity).to eq(4)
+    end
+
+    it "converts to Hart" do
+      expect(subject.convert_to("Hart").quantity).to eq(1.20411998265592)
+    end
+
+    it "converts to b" do
+      expect(subject.convert_to("b").quantity).to eq(4)
+    end
+
+    it "converts to B" do
+      expect(subject.convert_to("B").quantity).to eq(0.5)
+    end
+  end
+end
diff --git a/spec/unit_measurements_spec.rb b/spec/unit_measurements_spec.rb
index 2004822..de712e1 100644
--- a/spec/unit_measurements_spec.rb
+++ b/spec/unit_measurements_spec.rb
@@ -4,6 +4,6 @@
 
 RSpec.describe UnitMeasurements do
   it "has a valid version number" do
-    expect(UnitMeasurements::VERSION).to eq("4.8.0")
+    expect(UnitMeasurements::VERSION).to eq("4.9.0")
   end
 end
diff --git a/units.md b/units.md
index 848707c..25210f4 100644
--- a/units.md
+++ b/units.md
@@ -553,3 +553,16 @@ These units are defined in `UnitMeasurements::RadiationEquivalentDose`.
 |:--|:--|:--|
 | _1_ | _Sv*_ | _sievert, sieverts_ |
 | 2 | rem | röntgen equivalent man, roentgen equivalent man |
+
+## 48. Information entropy
+
+These units are defined in `UnitMeasurements::InformationEntropy`.
+
+| # | Name | Aliases |
+|:--|:--|:--|
+| 1 | b* | bit, bits |
+| 2 | B* | bytes, bytes |
+| _3_ | _nat_ | _nit, nepit, natural unit of information_ |
+| 4 | Sh | shannon, shannons |
+| 5 | Hart | hartley, ban, dit |
+| 6 | nybl | nibble, nibbles, nybble, nyble |