diff --git a/src/utility/lib/Functions.re b/src/utility/lib/Functions.re
new file mode 100644
index 00000000..3cf4537a
--- /dev/null
+++ b/src/utility/lib/Functions.re
@@ -0,0 +1,7 @@
+let interpolate =
+    (xMin: float, xMax: float, yMin: float, yMax: float, xIntended: float)
+    : float => {
+  let minProportion = (xMax -. xIntended) /. (xMax -. xMin);
+  let maxProportion = (xIntended -. xMin) /. (xMax -. xMin);
+  yMin *. minProportion +. yMax *. maxProportion;
+};