diff --git a/mstcalc.py b/mstcalc.py
new file mode 100644
index 00000000..7771d9f5
--- /dev/null
+++ b/mstcalc.py
@@ -0,0 +1,163 @@
+########################################
+#### Run using `python mstcalc.py` ####
+########################################
+
+import tkinter as tk
+
+precedence = {
+    '^': 8,
+    '*': 4, '/': 4, '%': 4,
+    '+': 2, '-': 2,
+    '(': 1,
+    '#': 0
+}
+
+def split_exp(expression):
+    nums = []
+    num = ""
+    prev_char = None
+    i = 0
+
+    while i < len(expression):
+        ch = expression[i]
+
+        if ch.isdigit() or ch == '.':
+            num += ch
+        elif ch == '-' and (prev_char is None or prev_char in ('(', '+', '-', '*', '/', '^', '%')):
+            if i + 1 < len(expression) and expression[i+1] == '(':
+                nums.append('-1')
+                nums.append('*')
+            else:
+                num = ch
+        else:
+            if num != "":
+                nums.append(num)
+                num = ""
+            if ch.strip():
+                nums.append(ch)
+
+        if ch.strip():
+            prev_char = ch
+        i += 1
+
+    if num != "":
+        nums.append(num)
+
+    return nums
+
+def is_number(s):
+    try:
+        float(s)
+        return True
+    except ValueError:
+        return False
+
+def infix_to_postfix(expression):
+    postfix = []
+    st = ['#']
+
+    spl = split_exp(expression)
+
+    for i in spl:
+        if is_number(i):
+            postfix.append(i)
+        elif i == '(':
+            st.append(i)
+        elif i == ')':
+            while st[-1] != '#' and st[-1] != '(':
+                postfix.append(st.pop())
+            if st[-1] == '(':
+                st.pop()
+        else:
+            while st[-1] != '#' and ((precedence[st[-1]] > precedence.get(i, 0)) or (precedence[st[-1]] == precedence.get(i, 0) and i != '^')):
+                postfix.append(st.pop())
+            st.append(i)
+
+    while st[-1] != '#':
+        postfix.append(st.pop())
+
+    return postfix
+
+def stack_eval(expression):
+    postfix = infix_to_postfix(expression)
+    
+    st = []
+    for i in postfix:
+        if is_number(i):
+            st.append(float(i))
+        else:
+            a = st.pop()
+            b = st.pop()
+            
+            if i == '+':
+                st.append(b + a)
+            elif i == '-':
+                st.append(b - a)
+            elif i == '*':
+                st.append(b * a)
+            elif i == '/':
+                st.append(b / a)
+            elif i == '%':
+                st.append(b % a)
+            elif i == '^':
+                st.append(b ** a)
+            else:
+                raise ValueError(f"Unknown operator: {i}")
+            
+    return st[0]
+
+def press_enter(event):
+    click("=")
+
+def click(button_text = None, event = None):
+    if button_text == "=":
+        try:
+            expr = entry.get()
+            result = stack_eval(expr)
+            entry.delete(0, tk.END)
+            entry.insert(tk.END, str(result))
+            
+        except Exception as e:
+            entry.delete(0, tk.END)
+            entry.insert(tk.END, "Error")
+            if entry.get() == "Error":
+                root.after(500, lambda: entry.delete(0, tk.END))
+    elif button_text == "C":
+        entry.delete(0, tk.END)
+    elif button_text == "√":
+        entry.insert(tk.END, "^(1/2)")
+    elif button_text == "1/x":
+        entry.insert(tk.END, "^(-1)")
+    elif button_text is not None:
+        entry.insert(tk.END, button_text)
+
+root = tk.Tk()
+root.title("Stack-Based Calculator")
+
+root.bind("<Return>", press_enter)
+root.bind("<BackSpace>", lambda e: entry.delete(len(entry.get())-1, tk.END))
+root.bind("<Escape>", lambda e: entry.delete(0, tk.END))
+
+entry = tk.Entry(root, width=20, font=("Arial", 16))
+entry.grid(row=0, column=0, columnspan=4)
+
+buttons = [
+    '7','8','9','/',
+    '4','5','6','*',
+    '1','2','3','-',
+    '0','.','=','+',
+    '%','^','√','1/x',
+    'C'
+]
+
+row = 1
+col = 0
+for b in buttons:
+    action = lambda x=b: click(x)
+    tk.Button(root, text=b, width=6, height=2, command=action, font=('Arial', 12), padx=3, pady=3).grid(row=row, column=col)
+    col += 1
+    if col > 3:
+        col = 0
+        row += 1
+
+root.mainloop()