diff --git a/src/elisa/infer/results.py b/src/elisa/infer/results.py
index 7f7db16..744c735 100644
--- a/src/elisa/infer/results.py
+++ b/src/elisa/infer/results.py
@@ -972,6 +972,10 @@ def _(p):
 
             fn_dic = {d: factory(d) for d in mapping.values()}
 
+        cov = self.covar(params=(), fn=fn_dic, method='hess')
+        std = {k: np.sqrt(cov.matrix[k, k]) for k in mapping.values()}
+        std = {k: std[v] for k, v in mapping.items()}
+
         if method == 'profile':
             if params is not None:
                 warnings.warn('params is ignored when using profile method')
@@ -1028,6 +1032,7 @@ def _(p):
 
         return {
             'mle': jax.tree.map(convert, mle_flux),
+            'std': jax.tree.map(convert, std),
             'intervals': jax.tree.map(convert, intervals),
             'errors': jax.tree.map(convert, errors),
             'cl': cl,
@@ -2618,6 +2623,9 @@ class MLEFlux(NamedTuple):
     mle: dict[str, Q] | dict[str, dict[str, Q]]
     """The model flux at MLE."""
 
+    std: dict[str, Q] | dict[str, dict[str, Q]]
+    """The errors of the model flux, calculated from Hessian matrix."""
+
     intervals: dict[str, tuple[Q, Q]] | dict[str, dict[str, tuple[Q, Q]]]
     """The confidence intervals of the model flux."""
 
@@ -2652,6 +2660,9 @@ class MLELumin(NamedTuple):
     mle: dict[str, Q] | dict[str, dict[str, Q]]
     """The model luminosity at MLE."""
 
+    std: dict[str, Q] | dict[str, dict[str, Q]]
+    """The errors of the model luminosity, calculated from Hessian matrix."""
+
     intervals: dict[str, tuple[Q, Q]] | dict[str, dict[str, tuple[Q, Q]]]
     """The confidence intervals of the model luminosity."""
 
@@ -2687,7 +2698,10 @@ class MLEEiso(NamedTuple):
     """Cosmology model used to calculate Eiso."""
 
     mle: dict[str, Q] | dict[str, dict[str, Q]]
-    r"""The model Eiso at MLE."""
+    """The model Eiso at MLE."""
+
+    std: dict[str, Q] | dict[str, dict[str, Q]]
+    """The errors of the model Eiso, calculated from Hessian matrix."""
 
     intervals: dict[str, tuple[Q, Q]] | dict[str, dict[str, tuple[Q, Q]]]
     """The confidence intervals of the model Eiso."""