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Crypto Slippage Calculator
Turn a quoted token amount and your chosen tolerance into a threshold. Choose the calculation convention explicitly. This worksheet does not fetch quotes, predict price impact or build transactions.
How it works & assumptions02 Read the result with its assumptions
- Entered quote
- Difference from quote
- Entered tolerance
- Smallest entered token unit
All modes round down to the entered token decimals. The actual transaction may use other rounding, fees or protection rules. Check the route and wallet's final threshold. This does not estimate price impact or actual execution.
Quote: up to 18 decimals and 10¹⁵; tolerance: up to 6 decimals. Non-zero precision beyond the entered token decimals is rejected. Threshold amounts use exact integer arithmetic. Educational calculation, not financial advice.
Calculate the threshold—not a prediction of the fill
A quote tells you an expected exchange amount at a point in time. A tolerance defines a boundary you are willing to accept under a particular calculation convention. Neither tells you that a swap will execute, or that the token is safe. This calculator starts with the quote you supply; it does not query pools or inspect a transaction.
Three conventions, explicitly separated
Let Q be the quoted token amount and s be the percentage tolerance divided by 100. The first two modes start with a quoted output. The last starts with a quoted input.
| Mode | Before rounding | What changes |
|---|---|---|
| Output decrease | Q × (1 − s) | Allowed percentage decrease in output quantity |
| Inverse price | Q ÷ (1 + s) | Allowed increase in the inverse exchange price |
| Input increase | Q × (1 + s) | Allowed percentage increase in input quantity |
The inverse-price convention is not a typo. For example, the archived Uniswap v3 SDK trade implementation uses this division when deriving an exact-input minimum output. That reference does not establish how every current wallet, router or swap type calculates a threshold. Match the convention to the transaction you are checking.
A 1,000-token quote at 0.5%
With six token decimals, output-decrease mode gives 1,000 × 0.995 = 995 tokens. Inverse-price mode gives 1,000 ÷ 1.005 = 995.024875621…, which becomes 995.024875 after rounding down. For a quoted input of 1,000 tokens, input-increase mode gives a maximum threshold of 1,005 tokens. These are hypothetical boundaries, not recommendations to use 0.5%.
Why the decimals field matters
Token transfers operate in whole smallest units. The worksheet converts your amount to integer units, calculates the boundary and rounds down in all three modes. A rounded minimum is slightly lower than the unrounded minimum; a rounded maximum is slightly lower than the unrounded maximum. The difference is less than one entered smallest unit. A zero-unit result is rejected instead of being presented as useful protection.
The label does not verify a contract or fetch its precision. Entering the wrong decimals can produce the wrong threshold. Amounts that require non-zero precision beyond your entered decimals are rejected. Use the actual transaction’s route-specific rules if they differ from this worksheet.
What this number leaves out
Uniswap distinguishes price impact from execution slippage. The quote may already include the trade’s effect on pool pricing. A tolerance is not an extra fee automatically charged, and increasing it does not improve liquidity. Gas, transfer taxes, routing fees and unusual token behaviour need their own checks.
Read slippage vs price impact before interpreting a large tolerance, or use the failed-swap receipt checklist if a transaction has already failed. Do not raise a limit solely to force an unfamiliar transaction through.