<p>Because every node in the Bitcoin network can count.</p>

<p>The reward schedule is not based on years, but on number of blocks.  The reward is halved every 210000 blocks.  See <a href="https://en.bitcoin.it/wiki/Controlled_supply" rel="nofollow">https://en.bitcoin.it/wiki/Controlled_supply</a>.  Every full node has all the blocks in the block chain, and thus knows how many blocks are between the current one and the genesis block, so they can easily calculate what the current reward is supposed to be.  This is coded into Bitcoin Core and other node and wallet software.</p>

<p>No central authority is needed.</p>

CC BY-SA 3.0
2016-10-19T12:42:41.677Z
2016-10-19T12:42:41.677Z
Nate Eldredge
<p>It is good that when a miner solves the block with a transaction( to self of 12.5(bitcoins)(current value) ) and then it propagate it in the network , then 1. how come everybody in the node knows that current value is 12.5 and blocked solved is it is valid ?? 
is there any authority which say that now 4 years are over then the value should be half ...??</p>

<bitcoind>
How does every node in the bitcoin network came to know that reward value is now 25 or 12.5 or so?
Killerbeans
# How does every node in the bitcoin network came to know that reward value is now 25 or 12.5 or so?

(Asked by: username_0 on 2016-10-19)

It is good that when a miner solves the block with a transaction( to self of 12.5(bitcoins)(current value) ) and then it propagate it in the network , then 1. how come everybody in the node knows that current value is 12.5 and blocked solved is it is valid ??
is there any authority which say that now 4 years are over then the value should be half ...??

**Tags:** bitcoind


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## 1 answers

### Answer by username_1 on 2016-10-19. Score: 2 | Accepted answer

Because every node in the Bitcoin network can count.

The reward schedule is not based on years, but on number of blocks. The reward is halved every 210000 blocks. See <https://en.bitcoin.it/wiki/Controlled_supply>. Every full node has all the blocks in the block chain, and thus knows how many blocks are between the current one and the genesis block, so they can easily calculate what the current reward is supposed to be. This is coded into Bitcoin Core and other node and wallet software.

No central authority is needed.


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