diff --git a/src/humulus/filters.py b/src/humulus/filters.py
index a8e2d24..8064afb 100644
--- a/src/humulus/filters.py
+++ b/src/humulus/filters.py
@@ -134,6 +134,21 @@ def sort_hops(hops, form=False):
     return hops_sorted
 
 
+def ferm_pct(fermentables):
+    """Adds a 'pct' to each fermentable in fermentables.
+
+    'pct' represents the total percentage a fermentable makes up of the grist.
+    """
+    total = 0
+    # Calculate total
+    for ferm in fermentables:
+        total += float(ferm['amount'])
+    # Add a pct to each ferm
+    for ferm in fermentables:
+        ferm['pct'] = 100*float(ferm['amount'])/total
+    return fermentables
+
+
 def create_filters(app):
     app.add_template_filter(recipe_og)
     app.add_template_filter(recipe_fg)
@@ -142,3 +157,4 @@ def create_filters(app):
     app.add_template_filter(recipe_abv)
     app.add_template_filter(recipe_srm)
     app.add_template_filter(sort_hops)
+    app.add_template_filter(ferm_pct)
diff --git a/src/humulus/templates/recipes/info.html b/src/humulus/templates/recipes/info.html
index ca8a46b..6264a85 100644
--- a/src/humulus/templates/recipes/info.html
+++ b/src/humulus/templates/recipes/info.html
@@ -122,14 +122,16 @@
         <th>Amount</th>
         <th>PPG</th>
         <th>Color</th>
+        <th>%</th>
       </tr>
     </thead>
-    {%- for fermentable in recipe.fermentables|sort(attribute='amount', reverse=True) -%}
+    {%- for fermentable in recipe.fermentables|ferm_pct|sort(attribute='amount', reverse=True) -%}
     <tr>
       <td>{{ fermentable.name }}</td>
       <td>{{ fermentable.amount|float|round(2) }} lb.</td>
       <td>{{ fermentable.ppg|float|round }}</td>
       <td>{{ fermentable.color|float|round(1) }}°L</td>
+      <td>{{ fermentable.pct|float|round(1) }}%</td>
     </tr>
     {%- endfor -%}
   </table>
diff --git a/tests/test_filters.py b/tests/test_filters.py
index 4f0b1cd..b6928df 100644
--- a/tests/test_filters.py
+++ b/tests/test_filters.py
@@ -103,3 +103,12 @@ def test_sort_hops():
 
     for num, hop in enumerate(sort_hops(hop_forms, form=True)):
         assert hop.name.data == str(num)
+
+
+def test_ferm_pct():
+    ferms = [{'amount': '4'}, {'amount': '2'}, {'amount': '2'}]
+    assert ferm_pct(ferms) == [
+        {'amount': '4', 'pct': 50.0},
+        {'amount': '2', 'pct': 25.0},
+        {'amount': '2', 'pct': 25.0}
+    ]