Model the impermanent loss from a 50/50 liquidity pool as one token's price moves, entirely in your browser, with dollar amounts, not just percent.
Depositing into a 50/50 liquidity pool and simply holding the same two tokens are not the same bet, and the gap between them shows up the moment either token’s price moves. Impermanent Loss Calculator puts a number on that gap: the constant-product formula every Uniswap-style AMM runs on means the pool automatically sells the token that’s going up and buys the one going down, so a pool holder ends up with less of the winner than someone who just held.
Run it before adding liquidity to a volatile pair, or after the fact to see whether the trading fees you earned actually covered what the price move cost you. Two prices and a deposit amount are all it needs.
Let k be the ratio between the new price and the deposit price. Impermanent loss is 2√k / (1+k) − 1, always zero or negative, and always the same for k and 1/k — a token doubling and a token halving produce an identical percentage loss, which is why the calculator shows the same number whether you enter 2× or 0.5×. At k = 4 the formula resolves to exactly −20%, one of the few round numbers on the curve and a useful gut-check that an implementation is correct.
The formula assumes a pure 50/50 constant-product pool with no trading fees, no concentrated-liquidity ranges, and no impermanent-loss protection some protocols bolt on — Uniswap v3 ranges and Curve-style stable pools both move away from this curve in ways this tool doesn’t model. Fees earned while providing liquidity are real money that can offset or exceed the loss shown here; this number is the cost side of that trade, not the whole picture.
Quick Price Multiple
Impermanent Loss
-5.72%
Price ratio
2.0000×
If you had HODLed
$15,000.00
Value in the pool
$14,142.14
You’d be $857.86 worse off in the pool than simply holding both tokens, before counting any trading fees earned.
This uses the standard 50/50 constant-product formula, 2√k / (1+k) - 1, where k is how much the price ratio between your two pooled tokens has moved since deposit. It assumes the pool has already rebalanced to the new price and ignores trading fees earned along the way, which in a busy pool can offset or exceed the loss shown here.