diff --git a/src/controllers.coffee b/src/controllers.coffee
index e970190..83a98a4 100644
--- a/src/controllers.coffee
+++ b/src/controllers.coffee
@@ -12,11 +12,12 @@ pertApp.controller 'pertDiagController', ($scope) ->
     if !data? then return
     nodes = data.days.map (x) -> {id: x, label: ""+x}
     connections = []
+    console.log data.criticalPaths
     data.activities.forEach (x) ->
       connections.push
         from: x.startDay, to: x.endDay
         label: x.id+" ("+(if x.permittedDelay > 0 then x.duration+"/"+(x.duration+x.permittedDelay) else x.duration)+")"
-        color: if !x.permittedDelay then 'red'
+        color: if x.critical then 'red' else if !x.permittedDelay then 'orange'
       if x.permittedDelay > 0
         connections.push
           from: x.endDay
diff --git a/src/pert.coffee b/src/pert.coffee
index 48e66f4..c320148 100644
--- a/src/pert.coffee
+++ b/src/pert.coffee
@@ -1,6 +1,7 @@
 class Pert
   constructor: (@list, @verbose) ->
     @days = []
+    @criticalPaths = []
 
   log: (x...) -> if @verbose then console.log chalk.bold("Pert:"), x...
   err: (x...) -> console.log chalk.bold (chalk.red "Pert:"), x...
@@ -64,6 +65,21 @@ class Pert
     item.chainedDelay = lowestFDelay + lowestCDelay
     return item.chainedDelay isnt olDelay
 
+  calculateCriticalPaths: (path) ->
+    @log "calculating path from",path
+    lastID = path[path.length - 1]
+    last = @toActivity lastID
+    if last.dependant? and last.dependant.length > 0
+      last.dependant.forEach (x) =>
+        ii = @toActivity x
+        unless ((ii.permittedDelay or 0) + (ii.chainedDelay or 0)) > 0
+          p = path; p.push x
+          @calculateCriticalPaths p
+    else
+      @log "calculated path", path
+      path.forEach (x) => @toActivity(x).critical = yes
+      @criticalPaths.push path
+
   # Find out which activity has the highest id
   highestID: => return @maxa(@list.map (x) -> x.id)
 
@@ -89,7 +105,11 @@ class Pert
         if @calculateDelays x
           finished = no
     @log "Done calculating delays. Took", i, "iterations"
-    results = activities: @list, days: @days
+    for x,i in @list
+      console.log x
+      if !x.depends? or x.depends.length is 0
+        @calculateCriticalPaths [x.id]
+    results = activities: @list, days: @days, criticalPaths: @criticalPaths
     if options?.json
       if cb? then cb(JSON.stringify results)
       JSON.stringify results
diff --git a/src/table.html b/src/table.html
index fa83db3..50af13f 100644
--- a/src/table.html
+++ b/src/table.html
@@ -5,7 +5,7 @@
     <td><b>Duration (days)</b></td>
     <td><b>Start Day</b></td>
     <td><b>Depends On</b></td>
-    <td><b>Dependent</b></td>
+    <td><b>Dependant</b></td>
     <td><b>End Day</b></td>
     <td><b>Free Delay</b></td>
     <td><b>Chained Delay</b></td>
@@ -16,7 +16,7 @@
     <td>{{item.duration}}</td>
     <td>{{item.startDay}}</td>
     <td>{{item.depends || "N/A"}}</td>
-    <td>{{item.dependent || "N/A"}}</td>
+    <td>{{item.dependant || "N/A"}}</td>
     <td>{{item.endDay}} --- {{item.endDay + (item.permittedDelay || 0) + (item.chainedDelay || 0)}}</td>
     <td>{{item.permittedDelay || 0}}</td>
     <td>{{item.chainedDelay || 0}}</td>