# Fees

*Fixed gas pricing, transaction costs, and Turnstile conversion behavior*

> **Note:** **Token names used in this page:**
>
> * **RUSD** is the native token and fee token on Radius.
> * **SBC** is an ERC-20 stablecoin used for transfers.
> * If an account has SBC but not enough RUSD for gas, the Turnstile can convert SBC to RUSD inline.

## Overview

Radius uses fixed gas pricing with low, predictable fees. A standard ERC-20 stablecoin transfer costs about 0.00010 USD on average.

Fees are paid in RUSD. If an account holds a convertible stablecoin such as SBC, Radius can automatically convert it inline through [the Turnstile](#turnstile) at a 1:1 value [^1].

[^1]: RUSD uses 18 decimals, while SBC uses 6. For SBC, 10^6 base units map to 10^18 base units of RUSD at the same face value.

| Parameter                      | Value               |
| ------------------------------ | ------------------- |
| Avg. stablecoin transfer cost  | 0.00010 USD         |
| Target SBC transfers per 1 USD | 10,000              |
| Gas price                      | 9.85998816e-10 RUSD |
| Gas used (avg. transfer)       | 101444              |

## Query gas price

Use the standard `eth_gasPrice` RPC method to fetch the current fixed gas price:

```bash
curl -X POST https://rpc.testnet.radiustech.xyz \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_gasPrice","params":[],"id":1}'
```

**Example response:**

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x3b9aca00"
}
```

The `result` is the gas price in wei (hex-encoded). `0x3b9aca00` = 1,000,000,000 wei = 1 gwei.

## Use with development tools

Radius accepts both legacy and EIP-1559 fee fields, and standard fee estimation works out of the box — viem, ethers.js, and wagmi land transactions with no gas overrides. The main exception is Hardhat v2, which benefits from a `gasPrice` line in its network config. See [Tooling configuration](/build/tooling.md) for setup instructions covering Foundry, viem, wagmi, Hardhat, and ethers.js.

## Turnstile

If a sender has SBC but not enough RUSD for gas, Radius runs an automatic, zero-fee inline conversion before executing the transaction [^2].

[^2]: If the account also lacks sufficient convertible stablecoin balance, the transaction fails.

One minimum conversion (0.01 SBC → 0.01 RUSD) covers roughly 1,000 standard transfers.

For the Turnstile mechanics (conversion limits, one-way behavior, balance methods, and RPC interactions), see [The Turnstile and balances](/reference/ethereum-compatibility.md#the-turnstile-and-balances).