diff --git a/comfy_extras/nodes_math.py b/comfy_extras/nodes_math.py
new file mode 100644
index 000000000..6417bacf1
--- /dev/null
+++ b/comfy_extras/nodes_math.py
@@ -0,0 +1,119 @@
+"""Math expression node using simpleeval for safe evaluation.
+
+Provides a ComfyMathExpression node that evaluates math expressions
+against dynamically-grown numeric inputs.
+"""
+
+from __future__ import annotations
+
+import math
+import string
+
+from simpleeval import simple_eval
+from typing_extensions import override
+
+from comfy_api.latest import ComfyExtension, io
+
+
+MAX_EXPONENT = 4000
+
+
+def _variadic_sum(*args):
+    """Support both sum(values) and sum(a, b, c)."""
+    if len(args) == 1 and hasattr(args[0], "__iter__"):
+        return sum(args[0])
+    return sum(args)
+
+
+def _safe_pow(base, exp):
+    """Wrap pow() with an exponent cap to prevent DoS via huge exponents.
+
+    The ** operator is already guarded by simpleeval's safe_power, but
+    pow() as a callable bypasses that guard.
+    """
+    if abs(exp) > MAX_EXPONENT:
+        raise ValueError(f"Exponent {exp} exceeds maximum allowed ({MAX_EXPONENT})")
+    return pow(base, exp)
+
+
+MATH_FUNCTIONS = {
+    "sum": _variadic_sum,
+    "min": min,
+    "max": max,
+    "abs": abs,
+    "round": round,
+    "pow": _safe_pow,
+    "sqrt": math.sqrt,
+    "ceil": math.ceil,
+    "floor": math.floor,
+    "log": math.log,
+    "log2": math.log2,
+    "log10": math.log10,
+    "sin": math.sin,
+    "cos": math.cos,
+    "tan": math.tan,
+    "int": int,
+    "float": float,
+}
+
+
+class MathExpressionNode(io.ComfyNode):
+    """Evaluates a math expression against dynamically-grown inputs."""
+
+    @classmethod
+    def define_schema(cls) -> io.Schema:
+        autogrow = io.Autogrow.TemplateNames(
+            input=io.MultiType.Input("value", [io.Float, io.Int]),
+            names=list(string.ascii_lowercase),
+            min=1,
+        )
+        return io.Schema(
+            node_id="ComfyMathExpression",
+            display_name="Math Expression",
+            category="math",
+            search_aliases=[
+                "expression", "formula", "calculate", "calculator",
+                "eval", "math",
+            ],
+            inputs=[
+                io.String.Input("expression", default="a + b", multiline=True),
+                io.Autogrow.Input("values", template=autogrow),
+            ],
+            outputs=[
+                io.Float.Output(display_name="FLOAT"),
+                io.Int.Output(display_name="INT"),
+            ],
+        )
+
+    @classmethod
+    def execute(
+        cls, expression: str, values: io.Autogrow.Type
+    ) -> io.NodeOutput:
+        if not expression.strip():
+            raise ValueError("Expression cannot be empty.")
+
+        context: dict = dict(values)
+        context["values"] = list(values.values())
+
+        result = simple_eval(expression, names=context, functions=MATH_FUNCTIONS)
+        # bool check must come first because bool is a subclass of int in Python
+        if isinstance(result, bool) or not isinstance(result, (int, float)):
+            raise ValueError(
+                f"Math Expression '{expression}' must evaluate to a numeric result, "
+                f"got {type(result).__name__}: {result!r}"
+            )
+        if not math.isfinite(result):
+            raise ValueError(
+                f"Math Expression '{expression}' produced a non-finite result: {result}"
+            )
+        return io.NodeOutput(float(result), int(result))
+
+
+class MathExtension(ComfyExtension):
+    @override
+    async def get_node_list(self) -> list[type[io.ComfyNode]]:
+        return [MathExpressionNode]
+
+
+async def comfy_entrypoint() -> MathExtension:
+    return MathExtension()
diff --git a/nodes.py b/nodes.py
index 5be9b16f9..0ef23b640 100644
--- a/nodes.py
+++ b/nodes.py
@@ -2449,6 +2449,7 @@ async def init_builtin_extra_nodes():
         "nodes_replacements.py",
         "nodes_nag.py",
         "nodes_sdpose.py",
+        "nodes_math.py",
     ]
 
     import_failed = []
diff --git a/requirements.txt b/requirements.txt
index 9a674fac5..7bf12247c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -24,6 +24,7 @@ av>=14.2.0
 comfy-kitchen>=0.2.7
 comfy-aimdo>=0.2.7
 requests
+simpleeval>=1.0
 
 #non essential dependencies:
 kornia>=0.7.1
diff --git a/tests-unit/comfy_extras_test/nodes_math_test.py b/tests-unit/comfy_extras_test/nodes_math_test.py
new file mode 100644
index 000000000..fa4cdcac3
--- /dev/null
+++ b/tests-unit/comfy_extras_test/nodes_math_test.py
@@ -0,0 +1,197 @@
+import math
+
+import pytest
+from collections import OrderedDict
+from unittest.mock import patch, MagicMock
+
+mock_nodes = MagicMock()
+mock_nodes.MAX_RESOLUTION = 16384
+mock_server = MagicMock()
+
+with patch.dict("sys.modules", {"nodes": mock_nodes, "server": mock_server}):
+    from comfy_extras.nodes_math import MathExpressionNode
+
+
+class TestMathExpressionExecute:
+    @staticmethod
+    def _exec(expression: str, **kwargs) -> object:
+        values = OrderedDict(kwargs)
+        return MathExpressionNode.execute(expression, values)
+
+    def test_addition(self):
+        result = self._exec("a + b", a=3, b=4)
+        assert result[0] == 7.0
+        assert result[1] == 7
+
+    def test_subtraction(self):
+        result = self._exec("a - b", a=10, b=3)
+        assert result[0] == 7.0
+        assert result[1] == 7
+
+    def test_multiplication(self):
+        result = self._exec("a * b", a=3, b=5)
+        assert result[0] == 15.0
+        assert result[1] == 15
+
+    def test_division(self):
+        result = self._exec("a / b", a=10, b=4)
+        assert result[0] == 2.5
+        assert result[1] == 2
+
+    def test_single_input(self):
+        result = self._exec("a * 2", a=5)
+        assert result[0] == 10.0
+        assert result[1] == 10
+
+    def test_three_inputs(self):
+        result = self._exec("a + b + c", a=1, b=2, c=3)
+        assert result[0] == 6.0
+        assert result[1] == 6
+
+    def test_float_inputs(self):
+        result = self._exec("a + b", a=1.5, b=2.5)
+        assert result[0] == 4.0
+        assert result[1] == 4
+
+    def test_mixed_int_float_inputs(self):
+        result = self._exec("a * b", a=1024, b=1.5)
+        assert result[0] == 1536.0
+        assert result[1] == 1536
+
+    def test_mixed_resolution_scale(self):
+        result = self._exec("a * b", a=512, b=0.75)
+        assert result[0] == 384.0
+        assert result[1] == 384
+
+    def test_sum_values_array(self):
+        result = self._exec("sum(values)", a=1, b=2, c=3)
+        assert result[0] == 6.0
+
+    def test_sum_variadic(self):
+        result = self._exec("sum(a, b, c)", a=1, b=2, c=3)
+        assert result[0] == 6.0
+
+    def test_min_values(self):
+        result = self._exec("min(values)", a=5, b=2, c=8)
+        assert result[0] == 2.0
+
+    def test_max_values(self):
+        result = self._exec("max(values)", a=5, b=2, c=8)
+        assert result[0] == 8.0
+
+    def test_abs_function(self):
+        result = self._exec("abs(a)", a=-7)
+        assert result[0] == 7.0
+        assert result[1] == 7
+
+    def test_sqrt(self):
+        result = self._exec("sqrt(a)", a=16)
+        assert result[0] == 4.0
+        assert result[1] == 4
+
+    def test_ceil(self):
+        result = self._exec("ceil(a)", a=2.3)
+        assert result[0] == 3.0
+        assert result[1] == 3
+
+    def test_floor(self):
+        result = self._exec("floor(a)", a=2.7)
+        assert result[0] == 2.0
+        assert result[1] == 2
+
+    def test_sin(self):
+        result = self._exec("sin(a)", a=0)
+        assert result[0] == 0.0
+
+    def test_log10(self):
+        result = self._exec("log10(a)", a=100)
+        assert result[0] == 2.0
+        assert result[1] == 2
+
+    def test_float_output_type(self):
+        result = self._exec("a + b", a=1, b=2)
+        assert isinstance(result[0], float)
+
+    def test_int_output_type(self):
+        result = self._exec("a + b", a=1, b=2)
+        assert isinstance(result[1], int)
+
+    def test_non_numeric_result_raises(self):
+        with pytest.raises(ValueError, match="must evaluate to a numeric result"):
+            self._exec("'hello'", a=42)
+
+    def test_undefined_function_raises(self):
+        with pytest.raises(Exception, match="not defined"):
+            self._exec("str(a)", a=42)
+
+    def test_boolean_result_raises(self):
+        with pytest.raises(ValueError, match="got bool"):
+            self._exec("a > b", a=5, b=3)
+
+    def test_empty_expression_raises(self):
+        with pytest.raises(ValueError, match="Expression cannot be empty"):
+            self._exec("", a=1)
+
+    def test_whitespace_only_expression_raises(self):
+        with pytest.raises(ValueError, match="Expression cannot be empty"):
+            self._exec("   ", a=1)
+
+    # --- Missing function coverage (round, pow, log, log2, cos, tan) ---
+
+    def test_round(self):
+        result = self._exec("round(a)", a=2.7)
+        assert result[0] == 3.0
+        assert result[1] == 3
+
+    def test_round_with_ndigits(self):
+        result = self._exec("round(a, 2)", a=3.14159)
+        assert result[0] == pytest.approx(3.14)
+
+    def test_pow(self):
+        result = self._exec("pow(a, b)", a=2, b=10)
+        assert result[0] == 1024.0
+        assert result[1] == 1024
+
+    def test_log(self):
+        result = self._exec("log(a)", a=math.e)
+        assert result[0] == pytest.approx(1.0)
+
+    def test_log2(self):
+        result = self._exec("log2(a)", a=8)
+        assert result[0] == pytest.approx(3.0)
+
+    def test_cos(self):
+        result = self._exec("cos(a)", a=0)
+        assert result[0] == 1.0
+
+    def test_tan(self):
+        result = self._exec("tan(a)", a=0)
+        assert result[0] == 0.0
+
+    # --- int/float converter functions ---
+
+    def test_int_converter(self):
+        result = self._exec("int(a / b)", a=7, b=2)
+        assert result[1] == 3
+
+    def test_float_converter(self):
+        result = self._exec("float(a)", a=5)
+        assert result[0] == 5.0
+
+    # --- Error path tests ---
+
+    def test_division_by_zero_raises(self):
+        with pytest.raises(ZeroDivisionError):
+            self._exec("a / b", a=1, b=0)
+
+    def test_sqrt_negative_raises(self):
+        with pytest.raises(ValueError, match="math domain error"):
+            self._exec("sqrt(a)", a=-1)
+
+    def test_overflow_inf_raises(self):
+        with pytest.raises(ValueError, match="non-finite result"):
+            self._exec("a * b", a=1e308, b=10)
+
+    def test_pow_huge_exponent_raises(self):
+        with pytest.raises(ValueError, match="Exponent .* exceeds maximum"):
+            self._exec("pow(a, b)", a=10, b=10000000)