Why it matters
Every transaction needs enough BOT to cover its fee, or it fails with “insufficient funds”. Knowing how fees are calculated also helps you set sensible values when a library doesn’t pick them for you.How it works
Gas works the same way as on Ethereum:- Gas used measures how much work a transaction does. A plain BOT transfer uses 21,000 gas. Deploying or calling a contract uses more.
- Gas price is how much BOT you pay per unit of gas, usually quoted in gwei (one billionth of a BOT).
- Fee = gas used × gas price.
These values can change. Always read them from the network rather than hard-coding them.
On 2026-10-02 testnet rejected transactions that paid less than 20 gwei. A legacy transaction at 1 gwei failed with
gasPrice too low, and an EIP-1559 transaction with a 1 gwei tip failed with transaction underpriced: effective gas tip 1000000000, minimum needed 20000000000. Treat the suggested price as the minimum.
Why fees are low
- Blocks are mostly empty, so there’s no competition for space and no fee spikes.
- The base fee stays at zero, so you pay only the fixed tip.
- Blocks come every 0.75 seconds, so a transaction rarely waits long.
Read the gas price
cast gas-price prints the value in wei: 20000000000 is 20 gwei.
Estimate a transaction’s cost
Ask the node how much gas a transaction will use, then multiply by the gas price.
So the 10 tBOT you can get from the BOT Chain faucet covers thousands of small transactions, and even the 0.1 tBOT from the Uzo Labs faucet covers about 100 small contract calls.
Setting fees yourself
Most tools set fees for you. viem, ethers, Foundry and MetaMask all read the network’s suggested values. If you set them by hand, use:Related pages
Get testnet tokens
Free tBOT for gas.
Supported EIPs
EIP-1559 and the other upgrades BOT Chain supports.
Send transactions
Send transactions from a frontend.
Gasless transactions
Let users act without holding BOT.