Electrum Segwit Transaction size

[TheQuin]

I'm using an Electrum wallet with Segwit bech32/base32 (bc1) addresses and sent a transaction:

f0dc723b3337523dfa61555f2d4c214a0b6b42e5699d1e39df11b699d61e2fa5

(Yes I know it is a low fee, I'm not in any hurry.)

According to Electrum, the transaction is 212 bytes.

According to blockchain.info the transaction is 374 bytes

According to blocktrail.com the transaction is 157 bytes

Does anybody know a) which one is correct? b) why the discrepancy?

[Abdussamad]

https://btc.com/f0dc723b3337523dfa61555f2d4c214a0b6b42e5699d1e39df11b699d61e2fa5

virtual size 212 bytes. raw transaction is 374 bytes

see this: https://github.com/bitcoin/bips/blob/master/bip-0141.mediawiki#Transaction_size_calculations

[TheQuin]

Thanks for the links Abdussamad. Am I correct in the assumption that I was correct to calculate the fee based on the virtual size? Also that the size displayed on blocktrail.com is just wrong.