diff --git a/app/models/user.py b/app/models/user.py
index df9b8bf..0072003 100644
--- a/app/models/user.py
+++ b/app/models/user.py
@@ -54,6 +54,8 @@ class Currency(enum.Enum):
 
     sheets = db.relationship("Sheet", viewonly=True)
 
+    calculation_enabled = db.Column(db.Boolean, default=True)
+
     @hybrid_property
     def password(self):
         return self.password_hash
diff --git a/app/views/calculator.py b/app/views/calculator.py
index 428d567..d34c18d 100644
--- a/app/views/calculator.py
+++ b/app/views/calculator.py
@@ -1,4 +1,5 @@
 from flask import Blueprint, render_template, request, jsonify
+from flask_login import current_user
 from rectpack import (
     skyline,
     guillotine,
@@ -88,8 +89,16 @@ def calculator(printshop: str = None):
 def calculate():
     data = request.json
 
+    anon_u = User.query.filter_by(username="anonymous_user_one_calc").first()
+
     log(log.INFO, "Validate required data [%s]", data)
 
+    if current_user.is_anonymous:
+        if not anon_u.calculation_enabled:
+            return jsonify({"message": "Calculator is busy right now. Login/register or try it later"}), 400
+        anon_u.calculation_enabled = False
+        anon_u.save()
+
     if not data.get("bins"):
         return jsonify({"message": "Bin(s) not found"}), 400
     elif not data.get("rectangles"):
@@ -222,4 +231,8 @@ def calculate():
         del bin["bin"]
     del result["algo"]
 
+    if current_user.is_anonymous:
+        anon_u.calculation_enabled = True
+        anon_u.save()
+
     return jsonify(result)
diff --git a/migrations/versions/ec58c3ac5211_user_calculation_enabled.py b/migrations/versions/ec58c3ac5211_user_calculation_enabled.py
new file mode 100644
index 0000000..03a7646
--- /dev/null
+++ b/migrations/versions/ec58c3ac5211_user_calculation_enabled.py
@@ -0,0 +1,28 @@
+"""user calculation_enabled
+
+Revision ID: ec58c3ac5211
+Revises: 26ea19152d95
+Create Date: 2023-11-03 13:06:10.868668
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'ec58c3ac5211'
+down_revision = '26ea19152d95'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column('users', sa.Column('calculation_enabled', sa.Boolean(), default=True, server_default='true'))
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_column('users', 'calculation_enabled')
+    # ### end Alembic commands ###
diff --git a/wsgi.py b/wsgi.py
index 97aa11a..6579b22 100644
--- a/wsgi.py
+++ b/wsgi.py
@@ -17,5 +17,16 @@ def example_command():
     print("Hello World!!!")
 
 
+@app.cli.command()
+def create_anonymous_user():
+    """Create anonymous user."""
+    user = models.User(
+        username="anonymous_user_one_calc",
+        email="anonymous_user_one_calc@anonymous_user_one_calc.com",
+    )
+    user.save()
+    print("Anonymous user created.")
+
+
 if __name__ == "__main__":
     app.run()