<p>I suppose this is the <a href="https://blockexplorer.com/block/00000000000743f190a18c5577a3c2d2a1f610ae9601ac046a38084ccb7cd721" rel="nofollow">culprit</a>. If we add the duplicate 50BTC that is missing and the first reward from block 21,000,000, we would have 10,500,000BTC in total.</p>

<p>However, my calculations would be: 21000000 blocks (ranging from Genesis Block <strong><em>0</em></strong>, to block 20,999,999) multiplied by 50 BTC, that would give us 10,500,000
With the duplicate transaction, that would be 10,499,950 BTC total.</p>

CC BY-SA 3.0
2012-11-30T13:21:52.673Z
IIRC there's another duplicate as well. If the OP's number is actually for block #210,000, this accounts for it.
theymos
CC BY-SA 3.0
2012-11-30T14:35:41.250Z
What is a duplicate transaction? How does it make some bitcoins invalid? Is there a thread that discusses this?
ripper234
CC BY-SA 3.0
2012-11-30T15:00:53.107Z
@ripper234 - This - http://bitcoin.stackexchange.com/questions/3030/two-blocks-two-transactions-same-hash
ThePiachu
CC BY-SA 3.0
2012-11-30T20:21:11.657Z
The output of the genesis block cannot be spent.
Pieter Wuille
CC BY-SA 3.0
2012-12-01T09:18:47.677Z
@PieterWuille Hmm, that's interesting. Any reason for that?
ThePiachu
CC BY-SA 3.0
2012-12-01T14:29:52.610Z
Nobody knows, and there is no explicit comment about it in Satoshi's source code. However, no full node to date would allow him to spend it. Perhaps it was deliberate.
Pieter Wuille
CC BY-SA 3.0
2012-11-30T13:14:30.297Z
2012-11-30T13:14:30.297Z
ThePiachu
<p><a href="http://mineforeman.com/2012/11/30/dissecting-bitcoin-block-210000/">This article</a> claims <code>there are now 10,499,925 bitcoin</code> (at the time of the reward drop from 50 to 25).</p>

<p>Weren't there supposed to be exactly 21,000,000 / 2 = 10,500,000 BTC mined at this point? What am I missing?</p>

<blockchain>
How many Bitcoins existed when block 209,999 was mined?
ripper234
# How many Bitcoins existed when block 209,999 was mined?

(Asked by: username_0 on 2012-11-30)

[This article](http://mineforeman.com/2012/11/30/dissecting-bitcoin-block-210000/) claims `there are now 10,499,925 bitcoin` (at the time of the reward drop from 50 to 25).

Weren't there supposed to be exactly 21,000,000 / 2 = 10,500,000 BTC mined at this point? What am I missing?

**Tags:** blockchain


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## 1 answers

### Answer by username_1 on 2012-11-30. Score: 4 | Accepted answer

I suppose this is the [culprit](https://blockexplorer.com/block/00000000000743f190a18c5577a3c2d2a1f610ae9601ac046a38084ccb7cd721). If we add the duplicate 50BTC that is missing and the first reward from block 21,000,000, we would have 10,500,000BTC in total.

However, my calculations would be: 21000000 blocks (ranging from Genesis Block ***0***, to block 20,999,999) multiplied by 50 BTC, that would give us 10,500,000
With the duplicate transaction, that would be 10,499,950 BTC total.

> **Comments:**
> **username_2**: IIRC there's another duplicate as well. If the OP's number is actually for block #210,000, this accounts for it.  
> **username_0**: What is a duplicate transaction? How does it make some bitcoins invalid? Is there a thread that discusses this?  
> **username_1**: @username_0 - This - http://bitcoin.stackexchange.com/questions/3030/two-blocks-two-transactions-same-hash  
> **username_3**: The output of the genesis block cannot be spent.  
> **username_1**: @username_3 Hmm, that's interesting. Any reason for that?  
> **username_3**: Nobody knows, and there is no explicit comment about it in Satoshi's source code. However, no full node to date would allow him to spend it. Perhaps it was deliberate.  

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