user6707: Blockchain.info gives you the options of 'frugal', 'normal' and 'generous' for setting miners fees and leave it slightly vague as to what the transaction fee will ultimately be.
I want to use their Make Outgoing Payments API to send payments but how can I know what they choose as a transaction fee?
What if I have 0.01 BTC in my wallet and want to send it all to an address. There won't be enough BTC left over for a fee. What happens then?

user8717: There really isn't a standard fee value. Various clients implement different amounts. For example on my MultiBit installation it's currently set to 0.0001 BTC per 1000 bytes of transaction size.
You must include a fee otherwise miners won't confirm your transaction.
For Blockchain.info's case, using their API, if you don't have the $fee parameter, Blockchain.info will automatically add 0.0005 BTC in fee, which is the default value.

All transactions include a 0.0005 BTC miners fee.

So if you send 0.01 BTC with their API, and don't specify the $fee parameter, it will add a 0.0005 fee to your transaction. 
EDIT This means you actually need at least 0.0105 BTC (0.01 + 0.0005) in your wallet to make the transaction. If you want to send all of the 0.01 BTC, you have to actually send 0.0095, otherwise the transaction won't go through.

6707: <p>Blockchain.info gives you the options of 'frugal', 'normal' and 'generous' for setting miners fees and leave it slightly vague as to what the transaction fee will ultimately be.</p>

<p>I want to use their <a href="https://blockchain.info/api/blockchain_wallet_api" rel="nofollow">Make Outgoing Payments API</a> to send payments but how can I know what they choose as a transaction fee?</p>

<p>What if I have 0.01 BTC in my wallet and want to send it all to an address. There won't be enough BTC left over for a fee. What happens then?</p>
 8717: <p>There really isn't a standard fee value. Various clients implement different amounts. For example on my MultiBit installation it's currently set to 0.0001 BTC per 1000 bytes of transaction size.</p>

<p>You must include a fee otherwise miners won't confirm your transaction.</p>

<p>For Blockchain.info's case, using their API, if you don't have the <code>$fee</code> parameter, Blockchain.info will automatically add 0.0005 BTC in fee, which is the default value.</p>

<blockquote>
  <p>All transactions include a 0.0005 BTC miners fee.</p>
</blockquote>

<p>So if you send 0.01 BTC with their API, and don't specify the $fee parameter, it will add a 0.0005 fee to your transaction. </p>

<p><strong>EDIT</strong> This means you actually need at least 0.0105 BTC (0.01 + 0.0005) in your wallet to make the transaction. If you want to send all of the 0.01 BTC, you have to actually send 0.0095, otherwise the transaction won't go through.</p>
