diff --git a/src/pymatgen/analysis/elasticity/elastic.py b/src/pymatgen/analysis/elasticity/elastic.py
index c4826a9dfdc..d54a82df76c 100644
--- a/src/pymatgen/analysis/elasticity/elastic.py
+++ b/src/pymatgen/analysis/elasticity/elastic.py
@@ -135,6 +135,8 @@ class ElasticTensor(NthOrderElasticTensor):
     in units of eV/A^3.
     """
 
+    eV_A3_to_GPa = Unit("eV ang^-3").get_conversion_factor(Unit("GPa"))
+
     def __new__(cls, input_array, tol: float = 1e-4) -> Self:
         """
         Create an ElasticTensor object. The constructor throws an error if the shape of
@@ -201,7 +203,7 @@ def y_mod(self) -> float:
         Calculates Young's modulus (in SI units) using the
         Voigt-Reuss-Hill averages of bulk and shear moduli.
         """
-        return 9.0e9 * self.k_vrh * self.g_vrh / (3 * self.k_vrh + self.g_vrh)
+        return 9.0e9 * self.k_vrh * self.g_vrh * self.eV_A3_to_GPa / (3 * self.k_vrh + self.g_vrh)
 
     def directional_poisson_ratio(self, n: ArrayLike, m: ArrayLike, tol: float = 1e-8) -> float:
         """
diff --git a/tests/analysis/elasticity/test_elastic.py b/tests/analysis/elasticity/test_elastic.py
index 90526a7edb9..83a6b5e5f91 100644
--- a/tests/analysis/elasticity/test_elastic.py
+++ b/tests/analysis/elasticity/test_elastic.py
@@ -94,7 +94,7 @@ def test_properties(self):
         # voigt notation tensor
         assert_allclose(self.elastic_tensor_1.voigt, self.voigt_1)
         # young's modulus
-        assert self.elastic_tensor_1.y_mod == approx(54087787667.160583)
+        assert self.elastic_tensor_1.y_mod == approx(8665818958507.804)
 
         # prop dict
         prop_dict = self.elastic_tensor_1.property_dict
@@ -127,7 +127,7 @@ def test_structure_based_methods(self):
         assert self.elastic_tensor_1.snyder_opt(struct) == approx(0.18937465)
         assert self.elastic_tensor_1.snyder_total(struct) == approx(18.25064540)
         # Clarke
-        assert self.elastic_tensor_1.clarke_thermalcond(struct) == approx(0.3450307)
+        assert self.elastic_tensor_1.clarke_thermalcond(struct) == approx(4.367299105244635)
         # Cahill
         cahill_thermal_cond = self.elastic_tensor_1.cahill_thermalcond(struct)
         assert cahill_thermal_cond == approx(0.37896275)