Constant-Product Price Impact Calculator
Under the constant-product model (x·y=k), estimate the average execution price and price impact of buying a token with quote currency (fees excluded).
Results
Fill in the inputs and click Calculate.
- Tokens Received
- –
- Avg Execution Price
- –
- Price Impact
- –
- Token Reserve After
- –
- Quote Reserve After
- –
Risk disclaimer
Real protocols add fees, slippage guards and routing; results are a constant-product approximation.
Why do large orders slip?
Pool reserves are finite: the more you buy, the higher the price is pushed, so the average fill exceeds the pre-trade price.
Under x·y=k, deeper reserves mean the same order moves the price far less.
How to use
- Enter the pool's token reserve (the asset you buy).
- Enter the pool's quote reserve (e.g. USDT).
- Enter how much quote currency you plan to spend.
- Click Calculate for tokens received, average price and price impact.
Formula
- Post-trade token reserve = x·y ÷ (y + spend)
- Tokens received = x − post-trade reserve
- Average price = spend ÷ tokens received
- Price impact = average price ÷ spot − 1
Example
Token reserve 1,000 and quote reserve 2,000, spending 50 → receive ≈ 24.39 at ≈ 2.05, impact ≈ 2.5%.
The same spend against a 10× deeper pool moves price far less.
FAQ
Fees included?
No. Real DEXs charge fees and may route or rebate part back; this page is pure price impact.
Where to find reserves?
Read them from the chain or a block explorer for your pool — values vary by pool and chain.