# How to calculate the price after trade on Uniswap?

I would like to get the price of a token after a swap. For example the price is now \$1, and I would like to see how much will be the price after my swap. Is the execution price what I need in this case?

Let's use this transaction as an example:

https://bscscan.com/tx/0xdd38b435d9840062db9106e23712873fa2da44c366fa737b17f7fc6d111ef076#eventlog

Here `172054109197` Zombie tokens were transferred to Zombie / BUSD LP in exchange for `6357581284196624466` BUSD tokens.

Here is the Swap event:

``````amount0In: 172054109197
amount1In: 0
amount0Out: 0
amount1Out: 6357581284196624466
``````

If we look at both (Zombie, BUSD) contracts, they both use 18 `decimals`, i.e. we can think of these values as:

`0.000000172` Zombie traded for `6.3575` BUSD

To understand the price impact, we need to look at the Zombie / BUSD LP reserves before and after the transaction.

Before:

``````reserve0: 1203765031
reserve1: 6402195517789394391
``````

After:

``````reserve0: 173257874228
reserve1: 44614233592769925
``````

We know (by looking at the LP contract) that `reserve0` represents Zombie token and `reserve1` represents BUSD token.

As we traded Zombie for BUSD, we have to add the amount being traded in to the first reserve and deduct the amount being traded for from the second reserve, i.e.

``````reserve0: 1203765031+172054109197=173257874228
reserve1: 6402195517789394391+6357581284196624466=44614233592769925
``````

This is how the Swap affected the reserves and therefore the price ratio.