diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..b25c15b
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+*~
diff --git a/calculator/.gitignore b/calculator/.gitignore
new file mode 100644
index 0000000..1ddbbca
--- /dev/null
+++ b/calculator/.gitignore
@@ -0,0 +1 @@
+calc
diff --git a/calculator/Makefile b/calculator/Makefile
new file mode 100644
index 0000000..4c389bc
--- /dev/null
+++ b/calculator/Makefile
@@ -0,0 +1,2 @@
+calc: *.cpp *.h
+	clang++ -std=c++20 -O0 -g -o calc *.cpp
diff --git a/calculator/Product.h b/calculator/Product.h
new file mode 100644
index 0000000..8772893
--- /dev/null
+++ b/calculator/Product.h
@@ -0,0 +1,17 @@
+#ifndef SATISFACTORY_PRODUCT_H
+#define SATISFACTORY_PRODUCT_H
+
+#include <string>
+
+class Product {
+public:
+	Product() {}
+	~Product() {}
+
+	std::string Name() const { return name; }
+
+private:
+	std::string name;
+};
+
+#endif
diff --git a/calculator/Recipe.cpp b/calculator/Recipe.cpp
new file mode 100644
index 0000000..3656239
--- /dev/null
+++ b/calculator/Recipe.cpp
@@ -0,0 +1,20 @@
+#include <exception>
+#include <format>
+#include <string>
+
+#include "Recipe.h"
+
+std::vector<std::pair<Product, float> > Recipe::Ingredients(float overclock)
+{
+	if(overclock < 0.0f || overclock > 2.5f)
+	{
+		auto error = std::format("Invalid overclock of {:.2f}%.", (overclock * 100.0f));
+		throw std::invalid_argument(error);
+	}
+
+	std::vector<std::pair<Product, float> > rtn;
+	for(const auto &ingredient : ingredients)
+		rtn.push_back({ingredient.first, ingredient.second * overclock});
+
+	return rtn;
+}
diff --git a/calculator/Recipe.h b/calculator/Recipe.h
new file mode 100644
index 0000000..81c87c7
--- /dev/null
+++ b/calculator/Recipe.h
@@ -0,0 +1,27 @@
+#ifndef SATISFACTORY_RECIPE
+#define SATISFACTORY_RECIPE
+
+#include "Product.h"
+
+#include <vector>
+
+class Recipe {
+public:
+	Recipe()
+		{
+			// TEST:
+			ingredients.push_back({Product(), 20.0});
+			ingredients.push_back({Product(), 4.0});
+			ingredients.push_back({Product(), 60.0});
+		}
+	~Recipe() {}
+
+	std::pair<Product, float> Produces() const { return produces; }
+	std::vector<std::pair<Product, float> > Ingredients(float overclock = 1.0f);
+
+private:
+	std::pair<Product, float> produces;
+	std::vector<std::pair<Product, float> > ingredients;
+};
+
+#endif
diff --git a/calculator/main.cpp b/calculator/main.cpp
new file mode 100644
index 0000000..acae5a8
--- /dev/null
+++ b/calculator/main.cpp
@@ -0,0 +1,15 @@
+#include <iostream>
+
+#include "Recipe.h"
+
+int main()
+{
+	Recipe test;
+	auto ingredients = test.Ingredients();
+	ingredients = test.Ingredients(2.5);
+
+	for(const auto &i : ingredients)
+		std::cout << i.first.Name() << ", " << i.second << std::endl;
+
+	return 0;
+}