diff --git a/src/calibration.h b/src/calibration.h
new file mode 100644
index 0000000..8df3756
--- /dev/null
+++ b/src/calibration.h
@@ -0,0 +1,6 @@
+#ifndef CALIBRATION_H
+#define CALIBRATION_H
+
+unsigned int get_calibration_sum(FILE *input_file);
+
+#endif /* CALIBRATION_H */