diff --git a/lib/bitcoin.py b/lib/bitcoin.py
index 1d297bac..560b2275 100644
--- a/lib/bitcoin.py
+++ b/lib/bitcoin.py
@@ -805,7 +805,10 @@ class Transaction:
         # return the balance for that tx
         is_send = False
         is_pruned = False
-        v_in = v_out = v_out_mine = 0
+
+        v_in_mine = 0    # sum of transaction inputs coming from my addresses
+        v_out = 0        # sum of all transaction outputs
+        v_out_mine = 0   # sum of outputs sent to my addresses
 
         for item in self.inputs:
             addr = item.get('address')
@@ -816,7 +819,7 @@ class Transaction:
                 if value is None:
                     is_pruned = True
                 else:
-                    v_in += value
+                    v_in_mine += value
             else:
                 is_pruned = True
                     
@@ -826,19 +829,9 @@ class Transaction:
             if addr in addresses:
                 v_out_mine += value
 
-        if not is_pruned:
-            # all inputs are mine:
-            fee = v_out - v_in
-            v = v_out_mine - v_in
-        else:
-            # some inputs are mine:
-            fee = None
-            if is_send:
-                v = v_out_mine - v_out
-            else:
-                # no input is mine
-                v = v_out_mine
-            
+        v = v_out_mine - v_in_mine
+        fee = None if is_pruned else v_out - v_in_mine
+
         return is_send, v, fee
 
     def as_dict(self):