diff --git a/docs/WavesKit.md b/docs/WavesKit.md
index 9a89558..bd85b4c 100644
--- a/docs/WavesKit.md
+++ b/docs/WavesKit.md
@@ -72,6 +72,7 @@
 |[txBroadcast](#waveskittxbroadcast)|Broadcasts a transaction|
 |[txBurn](#waveskittxburn)|Makes burn transaction as an array|
 |[txData](#waveskittxdata)|Makes data transaction as an array|
+|[txDiffs](#waveskittxdiffs)|Calculates a transaction address/assets/amounts diffs as an array|
 |[txEvaluate](#waveskittxevaluate)|Evaluates a transaction|
 |[txInvokeScript](#waveskittxinvokescript)|Makes invoke script transaction as an array|
 |[txIssue](#waveskittxissue)|Makes issue transaction as an array|
@@ -1824,7 +1825,7 @@ Makes asset script transaction as an array
 **Description**
 
 ```php
-public txBody (string $tx)
+public txBody (array $tx)
 ```
 
 Gets transaction body 
@@ -1833,7 +1834,7 @@ Gets transaction body
 
 **Parameters**
 
-* `(string) $tx`
+* `(array) $tx`
 : Transaction as an array  
 
 **Return Values**
@@ -1933,6 +1934,33 @@ Makes data transaction as an array
 <hr />
 
 
+### WavesKit::txDiffs  
+
+**Description**
+
+```php
+public txDiffs (array $tx)
+```
+
+Calculates a transaction address/assets/amounts diffs as an array 
+
+ 
+
+**Parameters**
+
+* `(array) $tx`
+: Transaction as an array  
+
+**Return Values**
+
+`array|false`
+
+> Calculated diffs as an array or FALSE on failure
+
+
+<hr />
+
+
 ### WavesKit::txEvaluate  
 
 **Description**
diff --git a/src/WavesKit.php b/src/WavesKit.php
index d7f3770..9dbf0c7 100644
--- a/src/WavesKit.php
+++ b/src/WavesKit.php
@@ -1180,6 +1180,51 @@ public function txEvaluate( $tx )
         return $json;
     }
 
+    private function txDiffsAmount( &$diffs, $address, $asset, $amount )
+    {
+        $diffs[$address][$asset] = $amount + ( isset( $diffs[$address][$asset] ) ? $diffs[$address][$asset] : 0 );
+    }
+
+    /**
+     * Calculates a transaction address/assets/amounts diffs as an array
+     *
+     * @param  array $tx Transaction as an array
+     *
+     * @return array|false Calculated diffs as an array or FALSE on failure
+     */
+    public function txDiffs( $tx, $caller = null, &$diffs = null )
+    {
+        if( $diffs === null )
+            $diffs = [];
+        
+        if( $caller === null )
+            $caller = $tx['sender'];
+
+        $dApp = $tx['dApp'];
+        $payments = $tx['payment'];
+        $stateChanges = $tx['stateChanges'];
+
+        foreach( $stateChanges['invokes'] as $tx )
+            $this->txDiffs( $tx, $dApp, $diffs );
+
+        foreach( $payments as $payment )
+        {
+            $amount = $payment['amount'];
+            $asset = isset( $payment['assetId'] ) ? $payment['assetId'] : 'WAVES';
+            $this->txDiffsAmount( $diffs, $caller, $asset, -$amount );
+            $this->txDiffsAmount( $diffs, $dApp, $asset, +$amount );
+        }
+        foreach( $stateChanges['transfers'] as $transfer )
+        {
+            $amount = $transfer['amount'];
+            $asset = isset( $transfer['asset'] ) ? $transfer['asset'] : 'WAVES';
+            $this->txDiffsAmount( $diffs, $dApp, $asset, -$amount );
+            $this->txDiffsAmount( $diffs, $transfer['address'], $asset, +$amount );
+        }
+
+        return $diffs;
+    }
+
     /**
      * Broadcasts a transaction
      *
@@ -2218,7 +2263,7 @@ private function getScriptFee( $tx )
     /**
      * Gets transaction body
      *
-     * @param  string $tx Transaction as an array
+     * @param  array $tx Transaction as an array
      *
      * @return string|false Body of the transaction or FALSE on failure
      */
diff --git a/test/selftest.php b/test/selftest.php
index dfe0f87..bbe9c1e 100644
--- a/test/selftest.php
+++ b/test/selftest.php
@@ -659,6 +659,12 @@ function getData( $wk, $key )
     $tx = $wk->txInvokeScript( '3MsABb4zvG6U2gczxt7y91XSzGGuZzmLxsi', 'retransmit', $args, $payments );
     $tx['version'] = 2;
     $tx = $wk->txSign( $tx );
+    {
+        $evtx = $wk->txEvaluate( $tx );
+        $evtxDiffs = $wk->txDiffs( $evtx );
+        $vtx = $wk->txValidate( $tx );
+        $vtxDiffs = $wk->txDiffs( $vtx );
+    }
     $tx = $wk->txBroadcast( $tx );
 
     $result &= $tx !== false;
@@ -666,4 +672,11 @@ function getData( $wk, $key )
     $t->test( $result );
 }
 
+$t->pretest( 'txDiffs' );
+{
+    $etx = $wk->ensure( $evtx );
+    $etxDiffs = $wk->txDiffs( $etx );
+    $t->test( -1 === $etxDiffs[$wk->getAddress()]['WAVES'] && $etxDiffs === $evtxDiffs && $etxDiffs === $vtxDiffs );
+}
+
 $t->finish();
\ No newline at end of file