diff --git a/src/sssom/util.py b/src/sssom/util.py
index 3dc20939..50a6f3a4 100644
--- a/src/sssom/util.py
+++ b/src/sssom/util.py
@@ -1712,3 +1712,68 @@ def pandas_set_no_silent_downcasting(no_silent_downcasting=True):
     except KeyError:
         # Option does not exist in this version of pandas
         pass
+
+
+#: A mapping from slots to the weight they have for calculating the FAIRness of a mapping
+FAIR_WEIGHTS: dict[str, float] = {
+    # required
+    "object_id": 1.0,
+    "predicate_id": 1.0,
+    "subject_id": 1.0,
+    "mapping_justification": 1.0,
+    # Not required, but important
+    "license": 1.0,
+    "author_id": 1.0,
+    "creator_id": 1.0,
+    "reviewer_id": 1.0,
+    "confidence": 1.0,
+    #
+    "publication_date": 1.0,
+    "mapping_date": 1.0,
+    "issue_tracker_item": 1.0,
+    "curation_rule": 1.0,
+    "curation_rule_text": 1.0,
+    "similarity_measure": 1.0,
+    "subject_preprocessing": 1.0,
+    "object_category": 1.0,
+    "subject_source_version": 1.0,
+    "mapping_source": 1.0,
+    "subject_match_field": 1.0,
+    "subject_source": 1.0,
+    "object_source": 1.0,
+    "object_source_version": 1.0,
+    "object_preprocessing": 1.0,
+    "object_match_field": 1.0,
+    "mapping_tool": 1.0,
+    "mapping_tool_version": 1.0,
+    "subject_type": 1.0,
+    "similarity_score": 1.0,
+    "mapping_provider": 1.0,
+    "match_string": 1.0,
+    "object_type": 1.0,
+    "subject_category": 1.0,
+    # These give extra context, but are not critical
+    "predicate_label": 0.1,
+    "object_label": 0.1,
+    "subject_label": 0.1,
+    # These don't matter / are not actionable for FAIR
+    "comment": 0.0,
+    "other": 0.0,
+    "creator_label": 0.0,
+    "reviewer_label": 0.0,
+    "author_label": 0.0,
+    # These might not be relevant, so don't penalize if missing
+    "predicate_modifier": 0.0,
+    "mapping_cardinality": 0.0,
+    "see_also": 0.0,
+}
+FAIR_TOTAL_WEIGHT = sum(FAIR_WEIGHTS.values())
+
+
+def calculate_fairness(mapping: SSSOM_Mapping) -> float:
+    """Calculate FAIRness of a mapping."""
+    s: float = sum(weight for key, weight in FAIR_WEIGHTS.items() if getattr(mapping, key, None))
+    # Penalize for using label fields instead of ID fields
+
+    rv: float = s / FAIR_TOTAL_WEIGHT
+    return rv
diff --git a/tests/test_utils.py b/tests/test_utils.py
index d2da2703..03df2822 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -27,7 +27,10 @@
 from sssom.io import extract_iris
 from sssom.parsers import parse_sssom_table
 from sssom.util import (
+    FAIR_WEIGHTS,
     MappingSetDataFrame,
+    _get_sssom_schema_object,
+    calculate_fairness,
     filter_out_prefixes,
     filter_prefixes,
     get_dict_from_mapping,
@@ -635,3 +638,32 @@ def test_infer_scoped_cardinality(self) -> None:
         expected = ["1:n", "1:n", "1:n", "1:n", "1:n", "1:n"]
         self.assertEqual(expected, list(msdf.df[MAPPING_CARDINALITY].values))
         self.assertNotIn(CARDINALITY_SCOPE, msdf.df.columns)
+
+
+class TestFAIRScore(unittest.TestCase):
+    """Test the FAIRness score."""
+
+    def test_complete_weighting(self) -> None:
+        """Test that there are weights for all fields."""
+        missing = set(_get_sssom_schema_object().mapping_slots).difference(FAIR_WEIGHTS)
+        if missing:
+            msg = "\n".join(missing)
+            self.fail(msg=f"missing weights for mapping fields: {msg}")
+
+    def test_mapping_weight(self) -> None:
+        """Test calculating the weight on a mapping."""
+        m1 = SSSOM_Mapping(
+            subject_id="DOID:0050601",
+            predicate_id="skos:exactMatch",
+            object_id="UMLS:C1863204",
+            mapping_justification=SEMAPV.ManualMappingCuration.value,
+        )
+        m2 = SSSOM_Mapping(
+            subject_id="DOID:0050601",
+            subject_label="ADULT syndrome",
+            predicate_id="skos:exactMatch",
+            object_id="UMLS:C1863204",
+            object_label="ADULT syndrome",
+            mapping_justification=SEMAPV.ManualMappingCuration.value,
+        )
+        self.assertLess(calculate_fairness(m1), calculate_fairness(m2))