diff --git a/The C Programming Language/1.15.c b/The C Programming Language/1.15.c
new file mode 100644
index 0000000..a53da8b
--- /dev/null
+++ b/The C Programming Language/1.15.c	
@@ -0,0 +1,24 @@
+#include <stdio.h>
+
+double to_fahr(double celsius)
+{
+	return (celsius * 9.0 / 5.0) + 32.0;
+}
+
+main()
+{
+	float fahr, celsius;
+	int lower, upper, step;
+
+	lower = 0;
+	upper = 300;
+	step = 20;
+
+	celsius = lower;
+	printf("%10s %7s\n", "Fahrenheit", "Celsius");
+	while (celsius <= upper)
+	{
+		printf("%10.0f %7.1f\n", to_fahr(celsius), celsius);
+		celsius = celsius + step;
+	}
+}