diff --git a/src/quantity/unit/freeunit.rs b/src/quantity/unit/freeunit.rs
new file mode 100644
index 0000000..f3615b3
--- /dev/null
+++ b/src/quantity/unit/freeunit.rs
@@ -0,0 +1,160 @@
+use std::hash::{Hash, Hasher};
+
+use crate::quantity::Scalar;
+use crate::quantity::Quantity;
+use super::UnitBase;
+use super::Prefix;
+use super::Unit;
+
+
+#[derive(Debug)]
+#[derive(Copy, Clone)]
+pub struct FreeUnit {
+	pub (in super) base: UnitBase,
+	pub (in super) prefix: Prefix
+}
+
+impl Hash for FreeUnit {
+	fn hash<H: Hasher>(&self, state: &mut H) {
+		self.base.hash(state);
+	}
+}
+
+impl Eq for FreeUnit {}
+impl PartialEq for FreeUnit {
+	fn eq(&self, other: &Self) -> bool {
+		self.base.eq(&other.base)
+	}
+}
+
+
+macro_rules! quick_base_factor {
+	(float, $u:expr, $s:expr, $( ($x:expr, $p:expr) ),* ) => {
+		Some(Quantity {
+			scalar: Scalar::new_float_from_string($s).unwrap(),
+			unit: Unit::from_array(&[
+				$(
+					(FreeUnit::from_base($x), Scalar::new_rational($p).unwrap()),
+				)*
+				(FreeUnit::from_base($u), Scalar::new_rational(-1f64).unwrap())
+			])
+		})
+	};
+
+	(rational, $u:expr, $s:expr, $( ($x:expr, $p:expr) ),* ) => {
+		Some(Quantity {
+			scalar: Scalar::new_float_from_string($s).unwrap(),
+			unit: Unit::from_array(&[
+				$(
+					(FreeUnit::from_base($x), Scalar::new_rational($p).unwrap()),
+				)*
+				(FreeUnit::from_base($u), Scalar::new_rational(-1f64).unwrap())
+			])
+		})
+	};
+}
+
+
+impl FreeUnit {
+	pub fn from_base(base: UnitBase) -> FreeUnit {
+		return FreeUnit { base, prefix: Prefix::None }
+	}
+
+	pub fn from_base_prefix(base: UnitBase, prefix: Prefix) -> FreeUnit { FreeUnit {base, prefix} }
+	pub fn set_prefix(&mut self, prefix: Prefix) { self.prefix = prefix; }
+	pub fn get_prefix(&self) -> Prefix { self.prefix }
+
+	pub fn same_with_prefix(&self, other: &FreeUnit) -> bool {
+		self.base.eq(&other.base) && self.prefix.eq(&other.prefix)
+	}
+
+
+	pub fn to_base_factor(&self) -> Quantity {
+		let q = match self.base {
+			// Returns the unit we need to multiply by to get a base
+			// unit, or `None` if this is already a base unit.
+			//
+			// Example:
+			// 1 foot  = 0.3048 m,
+			// so 1 ft * (0.3084 m / ft) will give meters.
+			//
+			// The units here MUST be in terms of base units.
+			// If they aren't, things will break.
+
+			UnitBase::Foot => quick_base_factor!(float,
+				UnitBase::Foot,
+				"0.3048",
+				(UnitBase::Meter, 1f64)
+			),
+
+			UnitBase::Inch => quick_base_factor!(float,
+				UnitBase::Inch,
+				"0.0254",
+				(UnitBase::Meter, 1f64)
+			),
+
+			UnitBase::Mile => quick_base_factor!(rational,
+				UnitBase::Mile,
+				"1609",
+				(UnitBase::Meter, 1f64)
+			),
+
+			UnitBase::Minute => quick_base_factor!(rational,
+				UnitBase::Minute,
+				"60",
+				(UnitBase::Second, 1f64)
+			),
+
+			UnitBase::Hour => quick_base_factor!(rational,
+				UnitBase::Hour,
+				"3600",
+				(UnitBase::Second, 1f64)
+			),
+
+			UnitBase::Day => quick_base_factor!(rational,
+				UnitBase::Day,
+				"86400",
+				(UnitBase::Second, 1f64)
+			),
+
+			// Only base units should be missing a conversion factor.
+			_ => None
+		};
+
+		let mut q = q.unwrap_or(Quantity::new_rational_from_string("1").unwrap());
+
+		let mut p = self.prefix.to_ratio();
+		p.insert_unit(FreeUnit::from_base(self.base), Scalar::new_rational(1f64).unwrap());
+		p.insert_unit(FreeUnit::from_base_prefix(self.base, self.prefix), Scalar::new_rational(-1f64).unwrap());
+		q *= p;
+
+		return q;
+	}
+}
+
+
+impl ToString for FreeUnit {
+	fn to_string(&self) -> String {
+		let s = match self.base {
+			UnitBase::Second => "s",
+			UnitBase::Meter => "m",
+			UnitBase::Gram => "g",
+			UnitBase::Ampere => "a",
+			UnitBase::Kelvin => "k",
+			UnitBase::Mole => "mol",
+			UnitBase::Candela => "c",
+
+			UnitBase::Foot => "ft",
+			UnitBase::Inch => "in",
+			UnitBase::Mile => "mile",
+
+			UnitBase::Hour => "hour",
+			UnitBase::Minute => "min",
+			UnitBase::Day => "day",
+		};
+
+		let p = self.prefix.to_string();
+
+		format!("{p}{s}")
+	}
+}
diff --git a/src/quantity/unit/mod.rs b/src/quantity/unit/mod.rs
new file mode 100644
index 0000000..352682e
--- /dev/null
+++ b/src/quantity/unit/mod.rs
@@ -0,0 +1,40 @@
+use std::hash::Hash;
+
+mod freeunit;
+mod prefix;
+mod unit;
+
+pub use prefix::Prefix;
+pub use unit::Unit;
+pub use freeunit::FreeUnit;
+
+
+
+#[derive(Hash)]
+#[derive(Debug)]
+#[derive(Copy, Clone)]
+#[derive(Eq, PartialEq)]
+pub enum UnitBase {
+	// Base Units
+	Second,
+	Meter,
+	Gram, // Technically kilogram, but that messes with our prefix system.
+	Ampere,
+	Kelvin,
+	Mole,
+	Candela,
+
+	// Length units
+	Inch,
+	Foot,
+	Mile,
+
+	// Time units
+	Minute,
+	Hour,
+	Day,
+	//Week,
+	//Month,
+}
+
+
diff --git a/src/quantity/unit/prefix.rs b/src/quantity/unit/prefix.rs
new file mode 100644
index 0000000..5d1b6f2
--- /dev/null
+++ b/src/quantity/unit/prefix.rs
@@ -0,0 +1,110 @@
+use crate::quantity::Quantity;
+
+
+
+#[derive(Hash)]
+#[derive(Debug)]
+#[derive(Copy, Clone)]
+#[derive(Eq, PartialEq)]
+pub enum Prefix {
+	None,
+
+	Quetta,
+	Ronna,
+	Yotta,
+	Zetta,
+	Exa,
+	Peta,
+	Tera,
+	Giga,
+	Mega,
+	Kilo,
+	Hecto,
+	Deka,
+
+	Deci,
+	Centi,
+	Milli,
+	Micro,
+	Nano,
+	Pico,
+	Femto,
+	Atto,
+	Zepto,
+	Yocto,
+	Ronto,
+	Quecto
+}
+
+
+impl Prefix {
+	pub fn to_ratio(&self) -> Quantity {
+		let q = Quantity::new_rational_from_string(match self {
+			Prefix::Quetta => "1e30",
+			Prefix::Ronna => "1e27",
+			Prefix::Yotta => "1e24",
+			Prefix::Zetta => "1e21",
+			Prefix::Exa => "1e18",
+			Prefix::Peta => "1e15",
+			Prefix::Tera => "1e12",
+			Prefix::Giga => "1e9",
+			Prefix::Mega => "1e6",
+			Prefix::Kilo => "1e3",
+			Prefix::Hecto => "1e2",
+			Prefix::Deka => "1e1",
+
+			Prefix::Deci => "1e-1",
+			Prefix::Centi => "1e-2",
+			Prefix::Milli => "1e-3",
+			Prefix::Micro => "1e-6",
+			Prefix::Nano => "1e-9",
+			Prefix::Pico => "1e-12",
+			Prefix::Femto => "1e-15",
+			Prefix::Atto => "1e-18",
+			Prefix::Zepto => "1e-21",
+			Prefix::Yocto => "1e-24",
+			Prefix::Ronto => "1e-27",
+			Prefix::Quecto => "1e-30",
+
+			Prefix::None => { "1" }
+		}).unwrap();
+
+		return q;
+
+	}
+}
+
+
+impl ToString for Prefix {
+	fn to_string(&self) -> String {
+		String::from(match self {
+			Prefix::Quetta => "Q",
+			Prefix::Ronna => "R",
+			Prefix::Yotta => "Y",
+			Prefix::Zetta => "Z",
+			Prefix::Exa => "E",
+			Prefix::Peta => "P",
+			Prefix::Tera => "T",
+			Prefix::Giga => "G",
+			Prefix::Mega => "M",
+			Prefix::Kilo => "k",
+			Prefix::Hecto => "h",
+			Prefix::Deka => "da",
+
+			Prefix::Deci => "d",
+			Prefix::Centi => "c",
+			Prefix::Milli => "m",
+			Prefix::Micro => "u",
+			Prefix::Nano => "n",
+			Prefix::Pico => "p",
+			Prefix::Femto => "f",
+			Prefix::Atto => "a",
+			Prefix::Zepto => "z",
+			Prefix::Yocto => "y",
+			Prefix::Ronto => "r",
+			Prefix::Quecto => "q",
+
+			Prefix::None => ""
+		})
+	}
+}
diff --git a/src/quantity/unit.rs b/src/quantity/unit/unit.rs
similarity index 50%
rename from src/quantity/unit.rs
rename to src/quantity/unit/unit.rs
index ad9bec5..4bf44a6 100644
--- a/src/quantity/unit.rs
+++ b/src/quantity/unit/unit.rs
@@ -1,298 +1,14 @@
 use std::collections::HashMap;
-use std::hash::{Hash, Hasher};
 use std::ops::{
 	Mul, Div,
 	MulAssign, DivAssign
 };
 
-use super::Scalar;
-use super::Quantity;
-
-
-#[derive(Hash)]
-#[derive(Debug)]
-#[derive(Copy, Clone)]
-#[derive(Eq, PartialEq)]
-pub enum UnitBase {
-	// Base Units
-	Second,
-	Meter,
-	Gram, // Technically kilogram, but that messes with prefix architecture.
-	Ampere,
-	Kelvin,
-	Mole,
-	Candela,
-
-	// Length units
-	Inch,
-	Foot,
-	Mile,
-
-	// Time units
-	Minute,
-	Hour,
-	Day,
-	//Week,
-	//Month,
-}
-
-#[derive(Hash)]
-#[derive(Debug)]
-#[derive(Copy, Clone)]
-#[derive(Eq, PartialEq)]
-pub enum Prefix {
-	None,
-
-	Quetta,
-	Ronna,
-	Yotta,
-	Zetta,
-	Exa,
-	Peta,
-	Tera,
-	Giga,
-	Mega,
-	Kilo,
-	Hecto,
-	Deka,
-
-	Deci,
-	Centi,
-	Milli,
-	Micro,
-	Nano,
-	Pico,
-	Femto,
-	Atto,
-	Zepto,
-	Yocto,
-	Ronto,
-	Quecto
-}
-
-impl Prefix {
-	pub fn to_ratio(&self) -> Quantity {
-		let q = Quantity::new_rational_from_string(match self {
-			Prefix::Quetta => "1e30",
-			Prefix::Ronna => "1e27",
-			Prefix::Yotta => "1e24",
-			Prefix::Zetta => "1e21",
-			Prefix::Exa => "1e18",
-			Prefix::Peta => "1e15",
-			Prefix::Tera => "1e12",
-			Prefix::Giga => "1e9",
-			Prefix::Mega => "1e6",
-			Prefix::Kilo => "1e3",
-			Prefix::Hecto => "1e2",
-			Prefix::Deka => "1e1",
-
-			Prefix::Deci => "1e-1",
-			Prefix::Centi => "1e-2",
-			Prefix::Milli => "1e-3",
-			Prefix::Micro => "1e-6",
-			Prefix::Nano => "1e-9",
-			Prefix::Pico => "1e-12",
-			Prefix::Femto => "1e-15",
-			Prefix::Atto => "1e-18",
-			Prefix::Zepto => "1e-21",
-			Prefix::Yocto => "1e-24",
-			Prefix::Ronto => "1e-27",
-			Prefix::Quecto => "1e-30",
-
-			Prefix::None => { "1" }
-		}).unwrap();
-
-		return q;
-
-	}
-}
-
-impl ToString for Prefix {
-	fn to_string(&self) -> String {
-		String::from(match self {
-			Prefix::Quetta => "Q",
-			Prefix::Ronna => "R",
-			Prefix::Yotta => "Y",
-			Prefix::Zetta => "Z",
-			Prefix::Exa => "E",
-			Prefix::Peta => "P",
-			Prefix::Tera => "T",
-			Prefix::Giga => "G",
-			Prefix::Mega => "M",
-			Prefix::Kilo => "k",
-			Prefix::Hecto => "h",
-			Prefix::Deka => "da",
-
-			Prefix::Deci => "d",
-			Prefix::Centi => "c",
-			Prefix::Milli => "m",
-			Prefix::Micro => "u",
-			Prefix::Nano => "n",
-			Prefix::Pico => "p",
-			Prefix::Femto => "f",
-			Prefix::Atto => "a",
-			Prefix::Zepto => "z",
-			Prefix::Yocto => "y",
-			Prefix::Ronto => "r",
-			Prefix::Quecto => "q",
-
-			Prefix::None => ""
-		})
-	}
-}
-
-
-#[derive(Debug)]
-#[derive(Copy, Clone)]
-pub struct FreeUnit {
-	base: UnitBase,
-	prefix: Prefix
-}
-
-impl Hash for FreeUnit {
-	fn hash<H: Hasher>(&self, state: &mut H) {
-		self.base.hash(state);
-	}
-}
-
-impl Eq for FreeUnit {}
-impl PartialEq for FreeUnit {
-	fn eq(&self, other: &Self) -> bool {
-		self.base.eq(&other.base)
-	}
-}
-
-
-macro_rules! quick_base_factor {
-	(float, $u:expr, $s:expr, $( ($x:expr, $p:expr) ),* ) => {
-		Some(Quantity {
-			scalar: Scalar::new_float_from_string($s).unwrap(),
-			unit: Unit::from_array(&[
-				$(
-					(FreeUnit::from_base($x), Scalar::new_rational($p).unwrap()),
-				)*
-				(FreeUnit::from_base($u), Scalar::new_rational(-1f64).unwrap())
-			])
-		})
-	};
-
-	(rational, $u:expr, $s:expr, $( ($x:expr, $p:expr) ),* ) => {
-		Some(Quantity {
-			scalar: Scalar::new_float_from_string($s).unwrap(),
-			unit: Unit::from_array(&[
-				$(
-					(FreeUnit::from_base($x), Scalar::new_rational($p).unwrap()),
-				)*
-				(FreeUnit::from_base($u), Scalar::new_rational(-1f64).unwrap())
-			])
-		})
-	};
-}
-
-
-impl FreeUnit {
-	pub fn from_base(base: UnitBase) -> FreeUnit {
-		return FreeUnit { base, prefix: Prefix::None }
-	}
-
-	pub fn from_base_prefix(base: UnitBase, prefix: Prefix) -> FreeUnit { FreeUnit {base, prefix} }
-	pub fn set_prefix(&mut self, prefix: Prefix) { self.prefix = prefix; }
-	pub fn get_prefix(&self) -> Prefix { self.prefix }
-
-	pub fn same_with_prefix(&self, other: &FreeUnit) -> bool {
-		self.base.eq(&other.base) && self.prefix.eq(&other.prefix)
-	}
-
-
-	pub fn to_base_factor(&self) -> Quantity {
-		let q = match self.base {
-			// Returns the unit we need to multiply by to get a base
-			// unit, or `None` if this is already a base unit.
-			//
-			// Example:
-			// 1 foot  = 0.3048 m,
-			// so 1 ft * (0.3084 m / ft) will give meters.
-			//
-			// The units here MUST be in terms of base units.
-			// If they aren't, things will break.
-
-			UnitBase::Foot => quick_base_factor!(float,
-				UnitBase::Foot,
-				"0.3048",
-				(UnitBase::Meter, 1f64)
-			),
-
-			UnitBase::Inch => quick_base_factor!(float,
-				UnitBase::Inch,
-				"0.0254",
-				(UnitBase::Meter, 1f64)
-			),
-
-			UnitBase::Mile => quick_base_factor!(rational,
-				UnitBase::Mile,
-				"1609",
-				(UnitBase::Meter, 1f64)
-			),
-
-			UnitBase::Minute => quick_base_factor!(rational,
-				UnitBase::Minute,
-				"60",
-				(UnitBase::Second, 1f64)
-			),
-
-			UnitBase::Hour => quick_base_factor!(rational,
-				UnitBase::Hour,
-				"3600",
-				(UnitBase::Second, 1f64)
-			),
-
-			UnitBase::Day => quick_base_factor!(rational,
-				UnitBase::Day,
-				"86400",
-				(UnitBase::Second, 1f64)
-			),
-
-			// Only base units should be missing a conversion factor.
-			_ => None
-		};
-
-		let mut q = q.unwrap_or(Quantity::new_rational_from_string("1").unwrap());
-
-		let mut p = self.prefix.to_ratio();
-		p.insert_unit(FreeUnit::from_base(self.base), Scalar::new_rational(1f64).unwrap());
-		p.insert_unit(FreeUnit::from_base_prefix(self.base, self.prefix), Scalar::new_rational(-1f64).unwrap());
-		q *= p;
-
-		return q;
-	}
-}
-
-
-impl ToString for FreeUnit {
-	fn to_string(&self) -> String {
-		let s = match self.base {
-			UnitBase::Second => "s",
-			UnitBase::Meter => "m",
-			UnitBase::Gram => "g",
-			UnitBase::Ampere => "a",
-			UnitBase::Kelvin => "k",
-			UnitBase::Mole => "mol",
-			UnitBase::Candela => "c",
-
-			UnitBase::Foot => "ft",
-			UnitBase::Inch => "in",
-			UnitBase::Mile => "mile",
-
-			UnitBase::Hour => "hour",
-			UnitBase::Minute => "min",
-			UnitBase::Day => "day",
-		};
-
-		let p = self.prefix.to_string();
-
-		format!("{p}{s}")
-	}
-}
+use crate::quantity::Scalar;
+use crate::quantity::Quantity;
+use super::UnitBase;
+use super::Prefix;
+use super::FreeUnit;
 
 #[derive(Debug)]
 #[derive(Clone)]
@@ -351,7 +67,6 @@ impl ToString for Unit {
 	}
 }
 
-
 impl Unit {
 	pub fn new() -> Unit {
 		return Unit {