The amount of slippage you should expect when swapping will depend on the size of the swap and the current market conditions. Generally speaking, the larger the swap, the higher the slippage you can expect. You should also take into account the liquidity of the market, as this can affect the amount of slippage you experience. As a general rule, you should always try to allocate extra funds to cover any potential slippage when making a swap. This will help to ensure that you don't end up with a loss due to unexpected price movements. Additionally, it's important to research the market and understand the current conditions before making any trades. This will help you to better anticipate any potential slippage and plan accordingly.