diff --git a/pkgs/applications/misc/calcoo/0001-javac-encoding.diff b/pkgs/applications/misc/calcoo/0001-javac-encoding.diff
new file mode 100644
index 00000000000..c16616b3dd0
--- /dev/null
+++ b/pkgs/applications/misc/calcoo/0001-javac-encoding.diff
@@ -0,0 +1,21 @@
+diff -Naur calcoo-2.1.0-old/build.xml calcoo-2.1.0-new/build.xml
+--- calcoo-2.1.0-old/build.xml	1969-12-31 21:00:01.000000000 -0300
++++ calcoo-2.1.0-new/build.xml	2022-04-16 15:41:59.763861191 -0300
+@@ -16,7 +16,7 @@
+     <!-- Create the build directory structure used by compile -->
+     <mkdir dir="${build}"/>
+     <!-- Compile the java code from ${src} into ${build} -->
+-    <javac srcdir="${src}" destdir="${build}" includeantruntime="false"/>
++    <javac srcdir="${src}" destdir="${build}" includeantruntime="false" encoding="iso-8859-1"/>
+   </target>
+ 
+   <target name="copyresource" depends="compile">
+@@ -31,7 +31,7 @@
+   <target name="testcompile">
+     <mkdir dir="${testbuild}"/>
+     <!-- Compile the java code from ${testsrc} into ${testbuild} -->
+-    <javac srcdir="${testsrc}" destdir="${testbuild}" includeantruntime="false">
++    <javac srcdir="${testsrc}" destdir="${testbuild}" includeantruntime="false" encoding="iso-8859-1">
+ 		<classpath>
+ 			<pathelement location="${junitpath}\junit.jar"/>
+ 			<pathelement location="${junitpath}\hamcrest-core.jar"/>
diff --git a/pkgs/applications/misc/calcoo/default.nix b/pkgs/applications/misc/calcoo/default.nix
new file mode 100644
index 00000000000..4af71bae653
--- /dev/null
+++ b/pkgs/applications/misc/calcoo/default.nix
@@ -0,0 +1,58 @@
+{ lib
+, stdenv
+, fetchzip
+, ant
+, jdk
+, makeWrapper
+}:
+
+stdenv.mkDerivation rec {
+  pname = "calcoo";
+  version = "2.1.0";
+
+  src = fetchzip {
+    url = "mirror://sourceforge/project/calcoo/calcoo/${version}/${pname}-${version}.zip";
+    hash = "sha256-Bdavj7RaI5CkWiOJY+TPRIRfNelfW5qdl/74J1KZPI0=";
+  };
+
+  patches = [
+    # Sets javac encoding option on build.xml
+    ./0001-javac-encoding.diff
+  ];
+
+  nativeBuildInputs = [
+    ant
+    jdk
+    makeWrapper
+  ];
+
+  dontConfigure = true;
+
+  buildPhase = ''
+    runHook preBuild
+
+    ant
+
+    runHook postBuild
+  '';
+
+  installPhase = ''
+    runHook preInstall
+
+    mkdir -p $out/bin $out/share/${pname}
+    mv dist/lib/calcoo.jar $out/share/${pname}
+
+    makeWrapper ${jdk}/bin/java $out/bin/calcoo \
+    --add-flags "-jar $out/share/${pname}/calcoo.jar"
+
+    runHook postInstall
+  '';
+
+  meta = with lib; {
+    homepage = "http://calcoo.sourceforge.net/";
+    description = "RPN and algebraic scientific calculator";
+    license = licenses.gpl2Plus;
+    maintainers = with maintainers; [ AndersonTorres ];
+    inherit (jdk.meta) platforms;
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 2dd0f9e3156..2cf7136f34e 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -5730,6 +5730,8 @@ with pkgs;
 
   uniscribe = callPackage ../tools/text/uniscribe { };
 
+  calcoo = callPackage ../applications/misc/calcoo { };
+
   galculator = callPackage ../applications/misc/galculator {
     gtk = gtk3;
   };