diff --git a/app/models/poll/stats.rb b/app/models/poll/stats.rb
index 9cc13c726..62b53a15b 100644
--- a/app/models/poll/stats.rb
+++ b/app/models/poll/stats.rb
@@ -21,6 +21,10 @@ class Poll::Stats
     total_participants_web + total_participants_booth
   end
 
+  def channels
+    CHANNELS.select { |channel| send(:"total_participants_#{channel}") > 0 }
+  end
+
   CHANNELS.each do |channel|
     define_method :"total_participants_#{channel}" do
       send(:"total_#{channel}_valid") +
@@ -58,7 +62,7 @@ class Poll::Stats
   end
 
   def total_letter_valid
-    0 # TODO
+    voters.where(origin: "letter").count # TODO: count only valid votes
   end
 
   def total_letter_white
diff --git a/app/views/polls/stats.html.erb b/app/views/polls/stats.html.erb
index da2a8351c..7fb485e83 100644
--- a/app/views/polls/stats.html.erb
+++ b/app/views/polls/stats.html.erb
@@ -29,7 +29,7 @@
         <div id="stats_by_channel" class="stats-group">
           <h4><%= t("stats.polls.by_channel") %></h4>
 
-          <% Poll::Stats::CHANNELS.each do |channel| %>
+          <% @stats.channels.each do |channel| %>
             <%= number_with_info_tags(
               @stats.send("total_participants_#{channel}"),
               t("stats.polls.#{channel}_percentage",
@@ -47,7 +47,7 @@
             <thead>
               <tr>
                 <th scope="col"><%= t("polls.show.stats.votes") %></th>
-                <% Poll::Stats::CHANNELS.each do |channel| %>
+                <% @stats.channels.each do |channel| %>
                   <th scope="col"><%= t("polls.show.stats.#{channel}") %></th>
                 <% end %>
                 <th scope="col"><%= t("polls.show.stats.total") %></th>
@@ -57,7 +57,7 @@
               <tr>
                 <th scope="row"><%= t("polls.show.stats.valid") %></th>
 
-                <% Poll::Stats::CHANNELS.each do |channel| %>
+                <% @stats.channels.each do |channel| %>
                   <td>
                     <%= @stats.send(:"total_#{channel}_valid") %>
                     <small><em>(<%= @stats.send(:"valid_percentage_#{channel}").round(2) %>%)</em></small>
@@ -73,7 +73,7 @@
               <tr>
                 <th scope="row"><%= t("polls.show.stats.white") %></th>
 
-                <% Poll::Stats::CHANNELS.each do |channel| %>
+                <% @stats.channels.each do |channel| %>
                   <td>
                     <%= @stats.send(:"total_#{channel}_white") %>
                     <small><em>(<%= @stats.send(:"white_percentage_#{channel}").round(2) %>%)</em></small>
@@ -87,7 +87,7 @@
               <tr>
                 <th scope="row"><%= t("polls.show.stats.null_votes") %></th>
 
-                <% Poll::Stats::CHANNELS.each do |channel| %>
+                <% @stats.channels.each do |channel| %>
                   <td>
                     <%= @stats.send(:"total_#{channel}_null") %>
                     <small><em>(<%= @stats.send(:"null_percentage_#{channel}").round(2) %>%)</em></small>
@@ -102,7 +102,7 @@
               <tr>
                 <th scope="row"><%= t("polls.show.stats.total") %></th>
 
-                <% Poll::Stats::CHANNELS.each do |channel| %>
+                <% @stats.channels.each do |channel| %>
                   <td>
                     <%= @stats.send(:"total_participants_#{channel}") %>
                     <small><em>(<%= @stats.send(:"total_participants_#{channel}_percentage").round(2) %>%)</em></small>
diff --git a/spec/models/poll/stats_spec.rb b/spec/models/poll/stats_spec.rb
index 720d70a8a..8199a593c 100644
--- a/spec/models/poll/stats_spec.rb
+++ b/spec/models/poll/stats_spec.rb
@@ -183,4 +183,50 @@ describe Poll::Stats do
       expect(stats.participants_by_geozone["Midgar"][:percentage]).to eq(33.333)
     end
   end
+
+  describe "#channels" do
+    context "no participants" do
+      it "returns no channels" do
+        expect(stats.channels).to eq []
+      end
+    end
+
+    context "only participants from web" do
+      before { create(:poll_voter, :from_web, poll: poll) }
+
+      it "returns the web channel" do
+        expect(stats.channels).to eq ["web"]
+      end
+    end
+
+    context "only participants from booth" do
+      before do
+        create(:poll_recount, :from_booth, poll: poll, total_amount: 1)
+      end
+
+      it "returns the booth channel" do
+        expect(stats.channels).to eq ["booth"]
+      end
+    end
+
+    context "only participants from letter" do
+      before { create(:poll_voter, origin: "letter", poll: poll) }
+
+      it "returns the web channel" do
+        expect(stats.channels).to eq ["letter"]
+      end
+    end
+
+    context "participants from all channels" do
+      before do
+        create(:poll_voter, :from_web, poll: poll)
+        create(:poll_recount, :from_booth, poll: poll, total_amount: 1)
+        create(:poll_voter, origin: "letter", poll: poll)
+      end
+
+      it "returns all channels" do
+        expect(stats.channels).to eq %w[web booth letter]
+      end
+    end
+  end
 end