What is Slippage?
Slippage is the difference between the price you expect to pay (or receive) for a token and the actual price at which your trade executes. In decentralized exchanges, slippage occurs because AMM pools shift price as trades consume liquidity.
Every DEX swap has two types of slippage:
- Price impact: The trade itself moves the pool price (larger trades = more impact)
- Front-running: MEV bots see your pending transaction and trade ahead of you
Slippage is one of the most important concepts for DeFi traders to understand — it can turn a “profitable” trade into a loss.
How Slippage Works
Price Impact
When you trade against a liquidity pool, you’re changing the ratio of tokens. The AMM formula (x × y = k) means larger trades create more price movement.
Example: Swapping $100 vs $100,000 worth of USDC for ETH in a pool:
| Trade Size | Pool TVL | Expected Price | Actual Price | Slippage |
|---|---|---|---|---|
| $100 | $10M | $3,000 | $3,000.01 | 0.003% |
| $10,000 | $10M | $3,000 | $3,001.50 | 0.05% |
| $100,000 | $10M | $3,000 | $3,015.08 | 0.50% |
| $1,000,000 | $10M | $3,000 | $3,155.24 | 5.17% |
As a rule of thumb: if your trade is more than 1% of the pool’s TVL, expect noticeable slippage.
Slippage Tolerance Setting
Every DEX wallet lets you set a slippage tolerance — the maximum percentage of slippage you’re willing to accept:
- 0.1-0.5%: Safe for stablecoin pairs and large pools
- 0.5-1%: Standard for most trades on established pairs (ETH/USDC)
- 1-3%: Acceptable for smaller cap tokens with less liquidity
- 5-10%: High risk — only for very illiquid tokens or during high volatility
- >10%: Almost always a mistake or a sign of a scam token
If actual slippage exceeds your tolerance, the transaction reverts automatically, protecting you from bad execution.
Front-Running and Sandwich Attacks
Beyond price impact, slippage is worsened by MEV (Maximal Extractable Value) extraction. When you submit a transaction to the mempool, MEV bots can see it and exploit it:
Sandwich Attack
- You submit a large buy order for TOKEN
- A MEV bot sees your transaction in the mempool
- Bot buys TOKEN first (front-running), pushing the price up
- Your order executes at the inflated price
- Bot sells TOKEN immediately after (back-running), profiting from the price difference
Result: You pay 2-5% more than necessary, and the bot pockets the difference.
Sandwich attacks extract an estimated $1M+ per day from DEX users. They’re especially common on Ethereum mainnet where mempool data is easily accessible.
How to Avoid Sandwich Attacks
- Use low slippage: Set slippage to 0.5% or less so sandwich bots can’t profit enough to justify the attack
- Use private mempools: Services like Flashbots Protect, MEV Blocker, or Merkle route your transactions privately, invisible to MEV bots
- Split large orders: Break a big trade into multiple smaller ones spread over time
- Trade on L2s: Arbitrum and Optimism have less MEV activity than Ethereum mainnet
- Use aggregator DEXs: 1inch and Matcha split trades across multiple pools to minimize slippage
Slippage on Different DEX Types
| DEX Type | Slippage Behavior | Best For |
|---|---|---|
| Uniswap V2 | Linear, predictable | Simple swaps |
| Uniswap V3 | Concentated ranges — slippage spikes at range edges | Tight ranges, stable pairs |
| Curve | Minimal slippage for similar-value tokens | Stablecoin swaps |
| 1inch (aggregator) | Optimizes across all DEXs | Best execution price |
Calculating Slippage
Slippage = (Expected Price - Actual Price) / Expected Price × 100%
For AMM pools with constant product formula (x × y = k), the exact price impact can be calculated as:
Price Impact = (Trade Amount / Pool Reserves) × 100%This is an approximation. For precise calculations, use our Gas Fee Calculator or a DEX simulator.
Frequently Asked Questions
Q: What’s a good slippage tolerance? A: 0.5% for major pairs (ETH/USDC), 1-3% for mid-cap tokens, 3-5% maximum for low-liquidity tokens. Never set it above 10% unless you know exactly what you’re doing.
Q: Why does my transaction keep reverting? A: Your slippage tolerance is too low for the current market conditions. Increase it slightly, or wait for lower volatility.
Q: Can I avoid slippage entirely? A: No. But you can minimize it by trading smaller sizes, using deeper pools, and avoiding volatile periods. Aggregators like 1inch also help.