If you are used to an exchange withdrawal and are moving Ethereum funds from your own wallet, budget ETH for the source transaction and POL for spending after arrival. A wallet signs each blockchain transaction directly, so bridge gas is charged to your address rather than taken from the transfer amount by an exchange. The official Polygon Bridge route is one way to move supported assets between Ethereum and Polygon PoS.
- Keep ETH on Ethereum for any token approval and the bridge deposit.
- Keep POL on Polygon PoS to make transactions after your funds arrive.
- Estimate each transaction separately; gas prices change with network demand.
Each side of the bridge has its own gas budget
Bridging is a transaction on the source chain followed by a credit on the destination chain, and each network charges for its own work. For an Ethereum-to-Polygon PoS transfer, you pay Ethereum gas to initiate the move; once the asset arrives, Polygon PoS uses POL for transactions such as sending tokens or using an app.
For a token transfer, the source side can require two transactions: an approval allowing the bridge contract to use that token, then the deposit itself. If you have already approved that token and contract, you may only need the deposit transaction. Moving ETH can follow a different contract path, so check the wallet’s current transaction estimate rather than assuming every asset takes the same number of steps.
Do not confuse the asset you bridge with the gas token. Bridging a stablecoin can leave you with that stablecoin on Polygon but no POL to spend. Likewise, having POL ready on Polygon does not pay for an Ethereum transaction. Polygon Bridge transfers are initiated on the source network, and source-chain gas must be available there.
Estimate the Ethereum cost from gas units and gwei
Ethereum gas is the amount of computation a transaction uses; gwei is the unit commonly used to quote its price. Ethereum.org’s gas documentation explains the calculation: gas units multiplied by the effective price per unit. The final charge depends on the transaction’s actual gas use and the network price when it is included.
For an illustrative calculation, suppose a token approval uses 50,000 gas and the deposit uses 180,000 gas, with both transactions priced at 20 gwei. Together, 230,000 × 20 gwei is 4,600,000 gwei, or 0.0046 ETH. If approval is already in place, the deposit in this example would cost 0.0036 ETH. These are example inputs, not a quote: contract complexity and Ethereum demand can change both figures.
Before signing, look at the estimated network fee in your wallet and confirm that your ETH balance can cover it while leaving some ETH for any other Ethereum transaction you still need to make. A wallet may show a maximum fee allowance; the amount actually charged can be lower if the transaction uses less gas. If the estimate changes while you wait, recalculate with the new estimate rather than relying on an earlier screenshot or a remembered average.
Arrive with POL for the first Polygon transaction
Plan a small POL balance on Polygon PoS in addition to the amount you want to bridge. The right reserve depends on what you intend to do next: one token transfer is a different workload from several contract interactions. Check the current estimate for that next action and leave a margin for a second transaction or a fee increase.
If you have no POL on Polygon, the bridged asset can still arrive, but you may be unable to move it or use an app until you obtain POL on that network. This is the self-custody equivalent of an exchange withdrawal arriving in an account that lacks the balance needed to send it onward. A source wallet’s ETH balance and a destination wallet’s POL balance are separate budgets, even when both wallets use the same address.
Polygon Support describes the native bridge as locking tokens on Ethereum and crediting a matching amount on Polygon PoS; the gas payment is separate from that asset movement. For an incoming transfer, decide in advance how you will fund the destination gas balance if you do not already hold POL there. The Polygon Bridge route may offer a way to include gas funding in a transfer, but check the current estimate and terms before relying on that option.
Check the transaction details before signing
Confirm that the wallet is using Ethereum for the source transaction and Polygon PoS for the destination, and check the asset and amount in the transaction summary. With an ERC-20 token, read the approval carefully: an approval authorizes a contract to spend that token, while the later deposit is the transaction that moves it into the bridge flow. Never share your recovery phrase to complete either step.
After signing, use the transaction hash to check the source transaction’s status in an Ethereum block explorer. A successful source transaction means it was included on Ethereum; it does not mean the destination balance has already updated. Wait for the bridge transfer to complete, then check the Polygon PoS address for the asset and POL before attempting another transaction.
Can I pay Ethereum gas with the token I am bridging?
Usually, no. Ethereum transactions require ETH for gas, including many token approvals and bridge deposits. The token being moved may be a stablecoin or another ERC-20 asset, but holding that token alone does not pay the Ethereum network fee. Check the wallet’s estimate before signing and make sure the sending address has enough ETH.
Do I need POL if I only want to receive tokens?
You do not need POL to receive a token at your Polygon PoS address. You will need POL to make a later Polygon transaction, such as sending that token to another address or interacting with an app. If you expect to use the funds soon, arrange a small POL balance before starting or decide how you will obtain it after arrival.
Why did my exchange withdrawal need only one fee?
An exchange can bundle network costs into its withdrawal process and present you with a single deduction or charge. With your own wallet, you authorize on-chain transactions yourself, and each network charges its own gas. A token approval can be a separate Ethereum transaction, while activity after arrival requires POL on Polygon PoS.