<p><code>input_value_in_base_units</code> is the number of satoshis that the input is worth. One Bitcoin is worth 100,000,000 satoshis.</p>

<p><code>input_age</code> is how many blocks the input has been present for. An unconfirmed transaction has an age of 0, and one that has 100 confirmations has an age of 100.</p>

CC BY-SA 3.0
2014-10-30T19:16:18.293Z
2014-10-30T19:16:18.293Z
Nick ODell
<p>From the Bitcoin wiki <a href="https://en.bitcoin.it/wiki/Transaction_fees#Technical_info">page on transaction fees</a>:</p>

<blockquote>
  <p>Transaction priority is calculated as a value-weighted sum of input
  age, divided by transaction size in bytes:</p>
  
  <p>priority = sum(input_value_in_base_units * input_age)/size_in_bytes
  Transactions need to have a priority above 57,600,000 to avoid the
  enforced limit</p>
</blockquote>

<p>Can somebody clarify what input_value_in_base_units or input_age is?</p>

<transaction-selection><coin-age-priority>
Bitcoin transaction priority calculation
Tor
# Bitcoin transaction priority calculation

(Asked by: username_0 on 2014-10-30)

From the Bitcoin wiki [page on transaction fees](https://en.bitcoin.it/wiki/Transaction_fees#Technical_info):

> Transaction priority is calculated as a value-weighted sum of input
> age, divided by transaction size in bytes:
>
> priority = sum(input\_value\_in\_base\_units \* input\_age)/size\_in\_bytes
> Transactions need to have a priority above 57,600,000 to avoid the
> enforced limit

Can somebody clarify what input\_value\_in\_base\_units or input\_age is?

**Tags:** transaction-selection, coin-age-priority


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## 1 answers

### Answer by username_1 on 2014-10-30. Score: 7 | Accepted answer

`input_value_in_base_units` is the number of satoshis that the input is worth. One Bitcoin is worth 100,000,000 satoshis.

`input_age` is how many blocks the input has been present for. An unconfirmed transaction has an age of 0, and one that has 100 confirmations has an age of 100.


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