diff --git a/apps/website/src/utils/historic/calculateDiff.ts b/apps/website/src/utils/historic/calculateDiff.ts
new file mode 100644
index 0000000..2dd95f2
--- /dev/null
+++ b/apps/website/src/utils/historic/calculateDiff.ts
@@ -0,0 +1,9 @@
+const calculateHistoricDiff = (currentPrice: number, percent: number) => {
+  let indexChange = Math.abs(percent) / 100
+  const dif = currentPrice * indexChange
+  const sign = Math.sign(percent) * -1
+
+  return currentPrice + sign * dif
+}
+
+export default calculateHistoricDiff