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New Member
posted Feb 13, 2023 2:51:49 PM

Calculation of coinbase transactions is wrong. The individual transactions are correct but the proceeds and cost basis are totally wrong. How do I fix this?

0 5 1061
5 Replies
Level 15
Feb 13, 2023 3:36:20 PM

wrong compared to what?

proceeds and cost basis are not calculated.

That is the data that you enter. gain/loss is the calculated value.

 

@noahliebs 

New Member
Feb 13, 2023 3:44:08 PM

The summary for Coinbase shows 3 things:

1. Total gain or loss 

2. Proceeds

3. Cost basis

 

This is generated by importing a CSV of transactions. eg: Buy, Sell, Interest, Reward, etc.

 

The proceeds and cost basis are both in the ballpark of $500k, but i didn't trade an amount anywhere near that. 

 

I fear that some sort of rounding error / floating point precision botched the calculation

New Member
Feb 13, 2023 3:47:19 PM

Resolved.

 

Instead of downloading from Coinbase from directly using my credentials I used, "Enter another way" and directly input the gains and losses.

Level 15
Feb 13, 2023 5:04:06 PM

I see you're saying you imported a large number of transactions, but the subtotal is wrong.

 

Yes, this can happen due to rounding errors that result from the way TurboTax does rounding.

 

To be off by $500,000 sounds pretty unlikely but what do I know.
I've never seen a coinbase csv file.

There must be something strange about the data in your csv file.

post a sample line for a couple of transactions.

also post the header line.

@noahliebs 

New Member
Feb 14, 2023 8:35:54 AM

There was nothing strange in the csv; I got it directly from Coinbase.

 

I narrowed it down to my SHIB transactions.

 

$500 of SHIB was 12,1 million coins. Before TurboTax compiles the buys and sells into taxable events, the numbers were correct. But as a transaction it basically said i bought $490,000 and sold for the exact same price. 

 

Sadly, there is no way for me to correct TurboTax's bad math