# Cannot calculate suggested fees for inner transactions

**URL:** <https://forum.algorand.co/t/cannot-calculate-suggested-fees-for-inner-transactions/5826>\
**Category:** General\
**Tags:** smart-contracts\
**Created:** [January 22, 2022, 8:05am UTC](https://forum.algorand.co/t/cannot-calculate-suggested-fees-for-inner-transactions/5826 "2022-01-22T08:05:41Z")\
**Posts on this page:** 1\
**Showing post:** 1

<div class="post-metadata">

**Author:** ![plasmatech8](https://avatars.discourse-cdn.com/v4/letter/p/45deac/32.png) [@plasmatech8](https://forum.algorand.co/u/plasmatech8)\
**Post date:** [January 22, 2022, 8:05am UTC](https://forum.algorand.co/t/cannot-calculate-suggested-fees-for-inner-transactions/5826/1 "2022-01-22T08:05:41Z")

</div>

I have an application call which contains inner transactions, written in PyTEAL.

I set the inner fee parameter to 0 so that the sender must pay for fees of the inner transaction and not use the funds held by the application.

```python
InnerTxnBuilder.Begin(),
InnerTxnBuilder.SetFields(
    {
        TxnField.type_enum: TxnType.Payment,
        TxnField.amount: amount,
        TxnField.receiver: reciever,
        # fee set to 0 to not use application funds
        TxnField.fee: Int(0)
    }
),
InnerTxnBuilder.Submit(),

```

But then it throws a `fee too small` error, because I still need to modify the suggested parameters when I construct the transaction so that the user pays for the fees for the additional transactions.

I figured that I need to increase `suggusted_params.fee` to include the fees of the inner transaction.

```python
suggusted_params = algod.suggested_params()
# pay additional fee for one inner transaction
suggusted_params.fee = "???"
txn = transaction.ApplicationNoOpTxn(
    sender=sender.address,
    sp=suggusted_params,
    index=application_id
)

```

## But the question is, how do I calculate the fee for the transaction?

Unless I am mistaken:

`suggusted_params.fee` is the fee per byte. However, the suggested params returns the value `"fee": 0` on all networks, so we cannot calculate the required fees. (My intention was to multiply it by 2 since I have 1 inner transaction, but obviously cannot since the value is 0).

`suggusted_params.min_fee` is the minimum fee that you must pay when the `bytes*fee` is low. However, it is not useful either because I need the fee per byte, not the minimum network fee.

I have found that in the dev sandbox network, I need the fee to be at least 10. But I do not wish to use a static value because the fees might increase in the future.

## Side note

Also, is this a good way to set an acceptable fee in PyTEAL? (Txn.fee is total fee, not fee per byte)

```python
has_acceptable_fee = Txn.fee() <= Global.min_txn_fee() * Int(100)
Assert(has_acceptable_fee)

```

On another note, I think the interchangability of “suggested fee” (per byte) and “fee” might cause confusion in some cases.

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