> ## Documentation Index
> Fetch the complete documentation index at: https://docs.theblockchainlibrary.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Estimate Gas with viem

> Estimate gas for contract interactions and check balance before sending.

# Estimate Gas with viem

Estimate gas for contract interactions and check balance before sending.

Estimate gas for contract interactions and check balance before sending.

## Explanation

estimateGas simulates a transaction to determine how much gas it will use. Always check balance before sending to avoid reverts. viem separates read (publicClient) and write (walletClient) concerns.

## Code

```typescript theme={null}
import { createPublicClient, createWalletClient, http, parseEther, formatEther } from "viem";
import { mainnet } from "viem/chains";
import { privateKeyToAccount } from "viem/accounts";

const account = privateKeyToAccount("0x...");

const publicClient = createPublicClient({ chain: mainnet, transport: http() });
const walletClient = createWalletClient({ account, chain: mainnet, transport: http() });

// Check balance
const balance = await publicClient.getBalance({ address: account.address });
console.log("Balance:", formatEther(balance), "ETH");

// Estimate gas for a transfer
const gasEstimate = await publicClient.estimateGas({
  account,
  to: "0x...recipient",
  value: parseEther("0.1"),
});
console.log("Estimated gas:", gasEstimate.toString());
```

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**Canonical knowledge ID:** `code-example:estimate-gas-viem`