diff --git a/Cargo.lock b/Cargo.lock
index 0a3da2e..33f56b5 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -138,7 +138,7 @@ dependencies = [
 
 [[package]]
 name = "kalk"
-version = "0.1.11"
+version = "0.2.0"
 dependencies = [
  "lazy_static",
  "phf",
@@ -149,7 +149,7 @@ dependencies = [
 
 [[package]]
 name = "kalk_cli"
-version = "0.1.10"
+version = "0.2.0"
 dependencies = [
  "ansi_term",
  "kalk",
diff --git a/README.md b/README.md
index e71dbe0..995285d 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@
 ![Build status](https://img.shields.io/travis/PaddiM8/kalk/master?label=build%20%26%20test)
 
 
-Kalk is a calculator (both program and library) that supports user-defined variables and functions.  
+Kalk is a calculator (both program and library) that supports user-defined variables, functions, and units (experimental).
 [Project kanban board (Kolan)](https://kolan.smrk.me/Board/4RAdMjLDz)
 
 ![](example.png)
@@ -15,6 +15,7 @@ Kalk is a calculator (both program and library) that supports user-defined varia
 * Groups: (), ⌈⌉, ⌋⌊
 * [Pre-defined functions and constants](https://github.com/PaddiM8/kalk/blob/master/kalk/src/prelude.rs)
 * User-defined functions and variables. `f(x, y) = xy`, `x = 5`
+* User-defined units (experimental). `unit m = cm/100`, `2m/50cm`, `50cm to m`
 * Understands fairly ambiguous syntax. Eg. `2sin50 + 2xy`
 * Syntax highlighting
 * Special-symbol completion on tab. Eg. write `sqrt` and press tab. It will be turned into `√`.
@@ -33,3 +34,30 @@ Run `cargo install kalk_cli`
 1. Go into the `kalk_cli` directory.
 2. Run `cargo build --release`
 3. Grab the binary from `targets/release`
+
+## Syntax
+
+### Functions
+__Defining:__ name(parameter1, parameter2, ...) = expression  
+**Example:** `f(x) = 2x+3`  
+
+__Using:__ name(argument1, argument2)  
+**Example:** `f(2)`  
+
+### Variables
+__Defining:__ name = expression  
+**Example:** `x = 3`  
+
+__Using:__ name  
+**Example:** `x`  
+
+### Units
+*Note: You only need to define the relationship between two units once. You will be able to convert between both of them.*
+__Defining:__ `unit` name = expression  
+**Example:** `unit deg = (rad*180)/π`  
+
+__Using:__ Use them freely in expressions.  
+**Example:** `2m/50cm`  
+
+__Converting:__ expression `to` unit  
+**Example:** `2 m to cm`  
diff --git a/kalk/Cargo.toml b/kalk/Cargo.toml
index 71577e8..e331d8c 100644
--- a/kalk/Cargo.toml
+++ b/kalk/Cargo.toml
@@ -1,10 +1,10 @@
 [package]
 name = "kalk"
-version = "0.1.11"
+version = "0.2.0"
 authors = ["PaddiM8"]
 edition = "2018"
 readme = "README.md"
-description = "A math evaluator library that supports user-defined functions and variables and can handle fairly ambiguous syntax."
+description = "A math evaluator library that supports user-defined functions, variables and units, and can handle fairly ambiguous syntax."
 repository = "https://github.com/PaddiM8/kalk/tree/master/kalk"
 license = "MIT"
 keywords = ["math", "calculator", "evaluator"]
diff --git a/kalk/src/interpreter.rs b/kalk/src/interpreter.rs
index f08b050..f238e8b 100644
--- a/kalk/src/interpreter.rs
+++ b/kalk/src/interpreter.rs
@@ -27,20 +27,27 @@ impl<'a> Context<'a> {
         statements: Vec<Stmt>,
     ) -> Result<Option<(Float, String)>, CalcError> {
         for (i, stmt) in statements.iter().enumerate() {
-            let value = eval_stmt(self, stmt);
+            let (value, unit) = eval_stmt(self, stmt)?;
 
             // Insert the last value into the `ans` variable.
-            self.symbol_table.set(
-                "ans",
+            self.symbol_table.set(if (&unit).len() > 0 {
                 Stmt::VarDecl(
                     String::from("ans"),
-                    Box::new(Expr::Literal(value.clone()?.to_string())),
-                ),
-            );
+                    Box::new(Expr::Unit(
+                        unit.clone(),
+                        Box::new(Expr::Literal(value.clone().to_string())),
+                    )),
+                )
+            } else {
+                Stmt::VarDecl(
+                    String::from("ans"),
+                    Box::new(Expr::Literal(value.clone().to_string())),
+                )
+            });
 
             if i == statements.len() - 1 {
                 if let Stmt::Expr(_) = stmt {
-                    return Ok(Some(value?));
+                    return Ok(Some((value, unit)));
                 }
             }
         }
diff --git a/kalk_cli/Cargo.toml b/kalk_cli/Cargo.toml
index 81bcf3c..950b395 100644
--- a/kalk_cli/Cargo.toml
+++ b/kalk_cli/Cargo.toml
@@ -1,10 +1,10 @@
 [package]
 name = "kalk_cli"
-version = "0.1.10"
+version = "0.2.0"
 authors = ["PaddiM8"]
 edition = "2018"
 readme = "../README.md"
-description = "A calculator that supports user-defined functions and variables and can handle fairly ambiguous syntax."
+description = "A calculator that supports user-defined functions, variables and units, and can handle fairly ambiguous syntax."
 repository = "https://github.com/PaddiM8/kalk"
 license = "MIT"
 keywords = ["math", "calculator", "cli", "command-line"]
@@ -15,7 +15,7 @@ path = "src/main.rs"
 name = "kalk"
 
 [dependencies]
-kalk = { path = "../kalk", version = "^0.1.11" }
+kalk = { path = "../kalk", version = "^0.2.0" }
 rustyline = "6.1.2"
 ansi_term = "0.12"
 regex = "1"