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# Formula for block reward when the block contains uncles?

Trying to find a simplified formula that explains exactly how the block reward is calculated for a block containing either one or two uncles.

Ethereum mining wiki lacks details. Best I could find was on github:

(U_n + 8 - B_n) * R / 8

Where:
R = 5 (ether)

But can someone explain what do U_n and B_n represent?

Why? Got a block reward from ethpool that was only ~3 eth I'm assuming because it contained 2 uncles.

• @ethead Uncles are a small percentage of blocks mined, so I doubt you'll find anyone interested enough to figure out the *exact* calculation in every situation. It is what it is.
• http://ethereum.stackexchange.com/q/569/87

U_n is the uncle number.
B_n is the block number.
R is the reward of 5 ETH.

if B_n = 1337 and R = 5
then U_0 = (1336 + 8 - 1337) * 5 / 8 == 4.375
and U_1 = (1335 + 8 - 1337) * 5 / 8 == 3.750
and so on
• Or to answer your question: you didnt recieve a block reward but an uncle reward.
• @dlehenky yes, uncles are generally small percentage. But it looks like ethpool currently has a 4.46% uncle rate:

`(1667 / (35703 + 1667)) * 100 = 4.46%`

Which means there's a decent amount of other miners on that pool being rewarded for uncle blocks and I'd like to verify the payouts are correct.

@5chdn thanks for the info! So let's try an example.

ethpool rewarded 3.09375 to 0xdeb5515fb01bf24d2f1dfb505c7e7f21798696cc for block 1071819. There were two uncles associated with the block: 1071816 and 1071817. So let's assume ethpool was really paying out a reward for the block's 2nd uncle, 1071817. So:

`(1071817 + 8 - 1071819) * 5 / 8 == 3.75`

So far so good. Now let's deduct ethpool's 1% fee:

`3.75 - (3.75 * .01) = 3.7125`

Still nowhere near the 3.09375 reward. So is ethpool skimming or did I miss something?
• Looked at it again, and ethpool actually mined the uncle block 1071816, which would make the formula:

`(1071816 + 8 - 1071819) * 5 / 8 == 3.125`

Then deduct the 1% fee:
```3.125 - (3.125 * .01) = 3.09375
```
So looks like it's all good. Thanks again for the help • @ethead ethpools uncle was at height 1071816 and not 1071817 (you can check with geth using eth.getUncle(1071819, 1)). This results in an reward of 3,125 (before fees).
• edited February 2016
Actually the reward you've got seems to be linked to the first uncle which was mined by ethpool (1071816)
`(1071816 + 8 - 1071819) * 5 / 8 == 3.125`
`3.125*0.99 == 3.09375`
Edit : Already two answers, guess i'm a bit slow 