Can you help or suggest the formula for calculation of simple multisig transactions?

I have an issue to calculate the size of multi signature  2-2 transaction.

I tried to follow this: 
https://bitcoin.stackexchange.com/questions/30570/predict-multi-signature-transaction-size answer, however it is vague and unclear. 
Here is my calculations:

     pubKeySize = 33;
     sigSize = 72;
     n = (m = 2);
     sizeOfRedeemScript = 1 + n * pubKeySize + 2;
     sizeOfScriptSig = 1 + m * (1 + sigSize) + 2 + sizeOfRedeemScript;
     sizeOfInput = 32 + 4 + 2 + sizeOfScriptSig + 4;
     sizeOfScriptPubKey = 2 + /** what is the length of script??  */ len(script);
     sizeOfOutput = 8 + sizeOfScriptPubKey;
     sizeOfTx = 4 + 2 + sizeOfInput + sizeOfOutput + 4;

If to be more precise I didn't get what is `SizeOfVarIntFor(lengthOfScript)` and what is the  `len(script)` (how to calculate it?)