Arc pays gas in USDC — what actually changes, including the decimals problem

Arc pays gas in USDC rather than a volatile native token, which makes fees dollar-denominated and predictable. The trap is decimals: USDC is 18 decimals as Arc's native gas asset and 6 decimals as an ERC-20, so 1e18 native equals 1e6 ERC-20. That mismatch is why wallet balances display incorrectly.

Almost nothing written about Arc explains the second half. It is the part that will cost you an hour of debugging, or a moment of unnecessary panic when a wallet tells you your balance is a trillion times bigger than it is.

One token, two interfaces

Every EVM chain has a native asset that pays for gas, and the EVM's plumbing — eth_getBalance, msg.value, gas accounting, the RPC layer — is built on the assumption that the native asset has 18 decimals. That is inherited from Ether and baked into essentially every library, wallet and block explorer written for Ethereum.

USDC has 6 decimals. It has had 6 decimals on every chain it has ever been issued on, and every integration in existence assumes that.

Circle's solution on Arc, which it describes as one token with two interfaces, is to expose the same USDC balance through both. At the native layer it is denominated in 18-decimal base units, so the EVM's assumptions hold and unmodified Ethereum tooling works. At the ERC-20 layer it is denominated in 6-decimal base units, so every existing USDC integration keeps working. One balance, one token, two representations of the same number.

That is a sensible engineering decision. It is also a decimal-shift landmine.

The arithmetic, precisely

The ratio between the two representations is 10¹² — a trillion. Everything below follows from that single number.

Why your wallet shows the wrong balance

A wallet renders a balance in two steps: fetch a raw integer, then divide by 10 raised to the number of decimals it believes the asset has. On Arc, there are two raw integers available for the same holding, and they differ by a factor of a trillion.

If a wallet fetches the native balance with eth_getBalance and then formats it as USDC using 6 decimals, it renders a number 10¹² times too large. Ten dollars of USDC shows as ten billion.

If tooling fetches the ERC-20 balanceOf and formats it with the 18 decimals it assumes a native gas asset has, it renders a number 10¹² times too small. Ten dollars shows as a rounding error near zero.

Both failure modes come from the same mismatch, and which one you see depends entirely on which interface your wallet happened to query and which decimal count it hardcoded. Neither means your funds moved. Before you conclude anything from a strange balance on Arc, check the same address on a block explorer, and check which interface each is reading. Wallets differ in how much of this they get right, which is a live version of the general point in MetaMask versus Rabby for EVM tokens: the display layer is software, and software makes assumptions.

The dust corollary

One implication is worth flagging, with the caveat that we are reasoning from the published unit relationship rather than quoting documented behaviour. The native representation is a trillion times finer-grained than the ERC-20 one. A native balance that is not an exact multiple of 10¹² base units cannot be represented exactly at the 6-decimal interface.

Gas accounting happens in native units. So sub-micro-dollar remainders — amounts smaller than 0.000001 USDC — can exist natively while being invisible or rounded at the ERC-20 interface. For a human trading a token, this is irrelevant: you are not going to miss a millionth of a cent. For anyone writing a script that reconciles balances across both interfaces and expects them to match exactly, it is a source of off-by-dust errors. Compare like with like, and do your arithmetic in native units.

What USDC gas changes about cost

Fees on Arc are quoted in Gwei, as on any EVM chain, but a Gwei on Arc is a billionth of a dollar rather than a billionth of an ETH. That single substitution changes the character of the fee market.

Circle's published testnet parameters set a minimum base fee of 20 Gwei and a hard ceiling of 20,000 Gwei — described in the documentation as a "hard ceiling that bounds worst-case cost" — with EIP-1559 pricing plus EWMA smoothing on top. Circle's stated target is roughly $0.01 per transaction. Twenty Gwei works out to 2 × 10⁻⁸ USDC per unit of gas, which is why fees at the floor are fractions of a cent regardless of how busy anything gets elsewhere.

Three things follow.

Your fee no longer depends on a second asset's price. On Ethereum or Base, a transaction's dollar cost is gas units × gas price × the price of ETH. Two of those three float. On Arc, the third term is gone: the fee is denominated in the same dollar-pegged asset you are already holding. Budgeting becomes arithmetic rather than forecasting.

You need USDC before you can do anything at all. There is no separate native gas token to acquire. That removes the classic "I bridged the token but have no gas" trap that catches people constantly on new chains, since bridging USDC in gets you the asset and the gas in one move. Arc's CCTP domain ID is 26 if you are moving USDC across with Circle's own transfer protocol.

The worst case is bounded, and the best case is not very good. A 20,000 Gwei ceiling means a congestion spike cannot produce the kind of fee event that makes a chain unusable for a day. But a 20 Gwei floor denominated in dollars also means fees cannot collapse the way they do on a chain whose gas asset is cheap and volatile. Predictability cuts in both directions, and for the specific case of high-frequency launch-and-churn trading, a stable dollar floor is not the advantage it sounds like. That is one of the four structural reasons set out in Arc chain memecoins and what Circle's L1 means.

None of this makes Arc expensive. It makes Arc not cheap in the way memecoin chains compete on being cheap, which is a different claim.

What it does not change

Gas is one line in a trade's cost. It is usually not the biggest one. Swap fees, price impact on a thin pool, slippage settings and MEV all survive the switch to USDC gas untouched, and on a new chain with shallow liquidity the second and third of those will dominate the first by orders of magnitude. The full breakdown is in how much it costs to buy a memecoin, and every line in it applies on Arc.

It also does not change the contract-level risks. A honeypot is a honeypot whether the gas is USDC or ETH.

What we do not know

Every fee figure above is a testnet parameter or a stated target, published before mainnet. Circle's documentation is explicit that "the values on this page apply to the Arc Testnet. Mainnet endpoints and parameters are published separately when available." Mainnet is scheduled for 16 September 2026. Fee behaviour under genuine load, and whether the minimum base fee carries over unchanged, are open questions as of 31 August 2026. Read a live quote in your wallet rather than trusting any number printed on a web page, including this one.

We also cannot tell you which wallets handle the dual-interface display correctly at mainnet, because mainnet does not exist yet. Test with a small amount first, and be sure you are on the real network — Circle has published a testnet chain ID but no mainnet chain ID, and several unofficial sites assert one they invented. Our Arc domain and endpoint verification guide covers which sources are real.

For Arc's fee design in the context it was actually built for — payments, settlement and capital markets rather than token trading — Radian goes deeper on the chain itself. Meme Central covers only the memecoin-adjacent slice; the deployment side is in the honest answer on launching a memecoin on Arc.

Frequently asked questions

Why does my Arc balance show a huge number?

Almost certainly a decimals mismatch, not a real balance. USDC on Arc is 18 decimals as the native gas asset and 6 decimals as an ERC-20. A wallet that reads the native balance and formats it with 6 decimals displays a figure 10¹² times too large. Check the same address on a block explorer before concluding anything.

How many decimals does USDC have on Arc?

Both six and eighteen, depending on which interface you query. As the native gas asset it uses 18 decimals so that standard EVM tooling works unmodified. As an ERC-20 it keeps USDC's canonical 6 decimals so existing integrations work. One native base unit is 10⁻¹² of one ERC-20 base unit.

Do you need a separate gas token on Arc?

No. Gas is paid in USDC, and there is no separate native gas asset to acquire first. The ARC token discussed in Circle's whitepaper has not launched, and Circle positions it as a staking and governance asset rather than a gas asset even in the exploratory case.

How much does a transaction cost on Arc?

Circle targets around $0.01 per transaction, with a 20 Gwei minimum base fee and a 20,000 Gwei ceiling on testnet as of 31 August 2026. Because fees are denominated in USDC, the cost does not move with a volatile gas asset's price. Mainnet parameters are unpublished — check a live quote.

---

Cheap gas is not the thing buyers check

Fee mechanics decide what a trade costs; they say nothing about whether a token's liquidity can be pulled out from under it. That is the check buyers actually run, and it is verifiable on-chain. Team Finance's fixed-term LP locking — built by TrustSwap, which also builds Meme Central — holds LP tokens for a set period on Ethereum, Robinhood Chain, Polygon, Base and BNB. Arc is not currently supported, and a lock proves only that the pool stays put, not that a developer will hold their own allocation.

---

Nothing here is financial, legal or tax advice. Memecoins are extremely high-risk: most lose most of their value, and the majority of tokens launched never reach a decentralised exchange at all. Never spend money you cannot afford to lose entirely. Meme Central does not recommend any specific token. Data described as Meme Central's own reflects tokens indexed by Meme Central and is not whole-market data.