<p>A transaction that has multiple output scripts that point to the same address would be no different from a transaction in which every output script pointed to a different address. So when you have two outputs to the same transaction, all that matters is that you have 2 outputs and the size of those outputs (byte-wise).</p>

<p><a href="https://en.bitcoin.it/wiki/Transaction_fees#Technical_info" rel="nofollow">Transaction priority</a> is calculated as follows:</p>

<p><code>priority = sum(input_value_in_base_units * input_age)/size_in_bytes</code></p>

<p>As you can see, only the tx size matters and the input value and age. None of these are influenced by the address to which coins are sent.</p>

CC BY-SA 3.0
2014-04-01T23:12:01.403Z
But the `cost` would be smaller if the two outputs in the question's example merge into a single output, right?
Doug Peters
CC BY-SA 3.0
2014-04-02T01:48:19.590Z
Well, yes. The cost is related to the priority. But for a 2-output tx, the cost will almost always be zero.
Steven Roose
CC BY-SA 3.0
2014-04-01T19:03:13.717Z
2014-04-01T19:03:13.717Z
Steven Roose
<p>A transaction <a href="https://bitcoin.stackexchange.com/questions/7603/can-a-single-transaction-have-multiple-outputs-going-to-the-same-address">can have multiple outputs pointing to the same address</a> however it's not clear to me if and how this affects the transaction's <strong><code>priority</code></strong> and <strong><code>cost</code></strong>? </p>

<p>As an example, let's consider these two simple cases:</p>

<ul>
<li><code>Case A</code>: Two outputs pointing to the same address use the same input in a 50/50 split.</li>
<li><code>Case B</code>: Two outputs pointing to the same address use two different inputs of equal amounts.</li>
</ul>

<transactions><transaction-fees><raw-transaction><coin-age-priority>
Cost of single vs multiple outputs to the same address
Doug Peters
# Cost of single vs multiple outputs to the same address

(Asked by: username_0 on 2014-04-01)

A transaction [can have multiple outputs pointing to the same address](https://bitcoin.stackexchange.com/questions/7603/can-a-single-transaction-have-multiple-outputs-going-to-the-same-address) however it's not clear to me if and how this affects the transaction's **`priority`** and **`cost`**?

As an example, let's consider these two simple cases:

* `Case A`: Two outputs pointing to the same address use the same input in a 50/50 split.
* `Case B`: Two outputs pointing to the same address use two different inputs of equal amounts.

**Tags:** transactions, transaction-fees, raw-transaction, coin-age-priority


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## 1 answers

### Answer by username_1 on 2014-04-01. Score: 0 | Accepted answer

A transaction that has multiple output scripts that point to the same address would be no different from a transaction in which every output script pointed to a different address. So when you have two outputs to the same transaction, all that matters is that you have 2 outputs and the size of those outputs (byte-wise).

[Transaction priority](https://en.bitcoin.it/wiki/Transaction_fees#Technical_info) is calculated as follows:

`priority = sum(input_value_in_base_units * input_age)/size_in_bytes`

As you can see, only the tx size matters and the input value and age. None of these are influenced by the address to which coins are sent.

> **Comments:**
> **username_0**: But the `cost` would be smaller if the two outputs in the question's example merge into a single output, right?  
> **username_1**: Well, yes. The cost is related to the priority. But for a 2-output tx, the cost will almost always be zero.  

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