<p>It is unclear, why someone has down voted, without leaving a comment...</p>

<p>When I look at the original bitcoin specs, I can see:" Added in Bitcoin Core 0.13.0 - The virtual transaction size. Differs from size for witness transactions". I tried to run through the page "<a href="https://bitcoin.org/en/release/v0.13.0" rel="nofollow noreferrer">https://bitcoin.org/en/release/v0.13.0</a>", but there was no mentioning of virtual size. So it seems to be hidden in one of the many SegWit additions. On <a href="https://bitcoincore.org/en/segwit_wallet_dev/" rel="nofollow noreferrer">https://bitcoincore.org/en/segwit_wallet_dev/</a> I finally found this:</p>

<p><strong>Transaction Fee Estimation</strong></p>

<pre><code>- Instead of transaction size, a new metric is defined, called “virtual size” (vsize)
- vsize of a transaction equals to 3 times of the size with original serialization, plus the size with new serialization, divide the result by 4 and round up to the next integer. For example, if a transaction is 200 bytes with new serialization, and becomes 99 bytes with marker, flag, and witness removed, the vsize is (99 * 3 + 200) / 4 = 125 with round up.
- vsize of a non-segwit transaction is simply its size
- Transaction fee should be estimated by comparing the vsize with other transactions, not the size.
- Developers should be careful not to make an off-by-4-times mistake in fee estimation.
</code></pre>

<p>Then I looked into </p>

<ul>
<li>blockchain.info </li>
<li>block explorer.com</li>
<li>live.blockcypher.com</li>
<li>www.blockcypher.com</li>
<li>www.blocktrail.com</li>
</ul>

<p>just to find out, they don't provide this value... </p>

CC BY-SA 3.0
2018-01-04T09:15:00.083Z
See also https://medium.com/@murchandamus/psa-wrong-fee-rates-on-block-explorers-48390cbfcc74
Pieter Wuille
CC BY-SA 3.0
2018-01-04T09:12:25.210Z
2018-01-04T09:12:25.210Z
pebwindkraft
<p>"The getrawtransaction RPC gets a hex-encoded serialized transaction or a JSON object describing the transaction."</p>

<p><a href="https://chainquery.com/bitcoin-api/getrawtransaction" rel="nofollow noreferrer">https://chainquery.com/bitcoin-api/getrawtransaction</a></p>

<p>The output includes the vsize (virtual size) of the transaction. Are there any blockchain parsers show the vsize?</p>

<transactions><transaction-fees><raw-data>
Are there any blockchain parsers which calculate virtual sizes of transactions?
timothyylim
# Are there any blockchain parsers which calculate virtual sizes of transactions?

(Asked by: username_0 on 2018-01-04)

"The getrawtransaction RPC gets a hex-encoded serialized transaction or a JSON object describing the transaction."

<https://chainquery.com/bitcoin-api/getrawtransaction>

The output includes the vsize (virtual size) of the transaction. Are there any blockchain parsers show the vsize?

**Tags:** transactions, transaction-fees, raw-data


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## 1 answers

### Answer by username_1 on 2018-01-04. Score: 1

It is unclear, why someone has down voted, without leaving a comment...

When I look at the original bitcoin specs, I can see:" Added in Bitcoin Core 0.13.0 - The virtual transaction size. Differs from size for witness transactions". I tried to run through the page "<https://bitcoin.org/en/release/v0.13.0>", but there was no mentioning of virtual size. So it seems to be hidden in one of the many SegWit additions. On <https://bitcoincore.org/en/segwit_wallet_dev/> I finally found this:

**Transaction Fee Estimation**

```
- Instead of transaction size, a new metric is defined, called “virtual size” (vsize)
- vsize of a transaction equals to 3 times of the size with original serialization, plus the size with new serialization, divide the result by 4 and round up to the next integer. For example, if a transaction is 200 bytes with new serialization, and becomes 99 bytes with marker, flag, and witness removed, the vsize is (99 * 3 + 200) / 4 = 125 with round up.
- vsize of a non-segwit transaction is simply its size
- Transaction fee should be estimated by comparing the vsize with other transactions, not the size.
- Developers should be careful not to make an off-by-4-times mistake in fee estimation.

```

Then I looked into

* blockchain.info
* block explorer.com
* live.blockcypher.com
* www.blockcypher.com
* www.blocktrail.com

just to find out, they don't provide this value...

> **Comments:**
> **username_2**: See also https://medium.com/@murchandamus/psa-wrong-fee-rates-on-block-explorers-48390cbfcc74  

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