How to use it
- Enter the amount to bridge, in CAD.
- Enter the bridge's percentage fee and any flat fee.
- Enter gas on the source chain and on the destination chain, in CAD.
- Enter the slippage you expect, as a percentage.
- Read the amount received and the cost percentage, and compare your amount with the 1% minimum.
What a bridge transfer costs
A bridge locks or burns tokens on one chain and releases or mints matching tokens on another, or routes your transfer through liquidity pools on both sides. You typically pay gas to start the transfer, a bridge fee (a percentage, a flat amount or both), sometimes gas on the destination chain, and slippage if the route swaps through a pool.
The calculator sorts these into percentage costs, which grow with the amount, and fixed costs, which do not. It reports the total, the amount received and the cost as a share of the transfer.
Worked example at three sizes
Illustrative inputs: a 0.1% bridge fee, a $2 flat fee, $8 of source-chain gas, $1 of destination-chain gas and 0.1% slippage, applied to three transfer sizes.
With these inputs, any transfer of $1,375 or more costs 1% or less: $11 of fixed costs divided by the 0.8% left over after percentage costs. Below that, the flat costs dominate, and a $500 transfer loses 2.40%.
| Amount | Percentage costs (0.2%) | Fixed costs | Total | Received | Cost |
|---|---|---|---|---|---|
| $500 | $1.00 | $11.00 | $12.00 | $488.00 | 2.40% |
| $2,000 | $4.00 | $11.00 | $15.00 | $1,985.00 | 0.75% |
| $20,000 | $40.00 | $11.00 | $51.00 | $19,949.00 | 0.26% |
Risk is not a fee
Fees are the visible cost. The bigger risk is the bridge itself. Bridges hold large pools of locked assets and rely on validators, multi-signature signers, relayers or outside messaging systems, and a failure in any of them can leave the tokens on the destination chain worth less than the originals or impossible to redeem. A wrapped token is only as good as the claim behind it. Read bridge risk before deciding how much to move at once.
Transfers can take anywhere from minutes to days, and during that time the funds are exposed to price moves and cannot be used. If you are moving to capture a price difference, see the cross-chain arbitrage calculator.
What the calculator leaves out
It does not include the cost of coming back (a return trip doubles the fixed costs), token approval transactions, or any discount at which the destination token trades against the original. Gas inputs are your estimates, and real network fees can vary widely. Use the gas breakeven calculator to check whether a higher yield on the other chain justifies the trip.
Check exactly which token you will receive. Two tokens with the same name on different chains may be issued by different bridges and are not interchangeable.
Before a large transfer, some users send a small test amount first. It costs another set of fixed fees, but it confirms the route, the destination address and the token received before the full amount is committed.
Canadian records
CRA's records guidance asks crypto-asset users to keep the address of each wallet they use and the details of each transaction, including the CAD value at the time. A bridge transfer touches two chains and often two addresses, so record both sides.
CRA has not published guidance on whether bridging or wrapping a token is a disposition. If the route swaps your token for a different one, the general rule that trading one crypto-asset for another is a disposition may apply. Keep detailed records and see capital vs business income.