diff --git a/Part_9/scripts/bmiCalculatorExpress.ts b/Part_9/scripts/bmiCalculatorExpress.ts
new file mode 100644
index 0000000..b37b6b8
--- /dev/null
+++ b/Part_9/scripts/bmiCalculatorExpress.ts
@@ -0,0 +1,29 @@
+interface bmiOutput {
+	bmi: number,
+	bmiRemark: string
+}
+
+export const calculateBmi = (height: number, weight: number): bmiOutput => {
+	const bmi: number = (weight / (height * height)) * 10000;
+	let bmiRemark;
+
+	if (bmi < 16) {
+		bmiRemark = 'You are Severely Under-Weight 💀';
+	} else if (16 < bmi && bmi < 18.4) {
+		bmiRemark = 'You are Under-Weight 😥';
+	} else if (18.5 < bmi && bmi < 24.9) {
+		bmiRemark = 'You are Healthy 😁';
+	} else if (25 < bmi && bmi < 29.9) {
+		bmiRemark = 'You are Over-Weight 😳';
+	} else if (30 < bmi && bmi < 34.9) {
+		bmiRemark = 'You are Moderately Obese 😰';
+	} else if (35 < bmi && bmi < 39.9) {
+		bmiRemark = 'You are Severely Obese 😨';
+	} else if (bmi > 40) {
+		bmiRemark = 'You are Morbidly Obese 💀';
+	} else {
+		throw new Error('Error occured while calculating BMI');
+	}
+
+	return { bmi: Number(bmi.toFixed(2)), bmiRemark }
+}
diff --git a/Part_9/scripts/index.ts b/Part_9/scripts/index.ts
index d1b2578..a7cd014 100644
--- a/Part_9/scripts/index.ts
+++ b/Part_9/scripts/index.ts
@@ -1,12 +1,33 @@
 import express from 'express';
-const app = express()
+const app = express();
+
+import { calculateBmi } from './bmiCalculatorExpress';
+
+app.use(express.json());
 
 app.get('/hello', (_req, res) => {
-	res.send('Hello Full Stack!')
+	res.send('Hello Full Stack!');
+})
+
+app.get ('/bmi', (req, res) => {
+	const { height, weight } = req.query
+
+	if (!height || !weight) {
+		return res.status(400).send({
+			error: 'Malformatted or Missing Parameters'
+		})
+	}
+	
+	try {
+		const {bmi, bmiRemark } = calculateBmi(Number(height), Number(weight))
+		return res.status(200).json({ height, weight, bmi, bmiRemark})
+	} catch (error) {
+		return res.status(400).send({ error: error.message })
+	}
 })
 
 const PORT = 3003
 
 app.listen(PORT, () => {
-	console.log(`Server running at Port ${PORT}`)
+	console.log(`Server running at Port ${PORT}`);
 })