Keep enough TRX to cover the network resources your swap cannot get elsewhere. The amount depends on the contract work and your wallet’s available resources. For the separate choice between wallet apps and exchanges, read how TRON swap compares with exchanges; this guide focuses on estimating the TRX balance.
tronswap.dev is a service for swapping TRX and TRC-20 USDT directly from your wallet. Before using any wallet-connected service, check the network estimate shown for the transaction you are about to approve.
A TRON swap uses two network resources: bandwidth and energy. Bandwidth covers the transaction’s data; energy covers the work a smart contract performs. A TRC-20 token such as USDT uses a smart contract, so its transfer or swap needs energy.
When you approve a swap, your wallet signs a transaction that calls a contract. The network first uses any energy or bandwidth available to your account, including resources delegated to it. If those resources fall short, TRON can burn TRX from your wallet to cover the gap.
Imagine your wallet shows an estimate of 75,000 energy for a swap, but only has 20,000 available. The shortfall is 55,000 energy. At a rate of 100 sun per energy, where 1 TRX equals 1,000,000 sun, that shortfall would cost 5.5 TRX if paid entirely through burning.
Those figures are an example, not a fixed USDT swap price. The energy estimate can change with the contract’s work and the wallet’s resources. The network’s fee rate can also change, so use the estimate for your specific transaction rather than relying on an old calculation.
Check whether the estimate includes each transaction the swap needs. On a first use, a token may require a separate approval transaction before the swap. That approval uses network resources too. If a contract call fails, it can still use energy, so read the wallet’s estimate and transaction details before signing.
Usually, you need some way to cover the network resources, even if you are swapping USDT for another token. That can be available energy or bandwidth, delegated resources, or TRX for the network to burn. Check the estimate in your wallet before approving the transaction.
The estimate depends on the contract work needed for that transaction and the resources already available to your wallet. A swap can take a different path from a simple token transfer. The contract may also share some energy costs, so two swaps for the same token amount can show different estimates.
Yes, if you expect to make another transaction on TRON. Sending or swapping TRC-20 tokens can require energy and bandwidth, and a future transaction may need TRX if your account lacks those resources. Keep enough for the next transaction you plan to make, based on its wallet estimate.