L2 Gas Tracker
2026-09-17 · By L2 Gas Tracker Research

Aave on Base and Arbitrum: Supply, Borrow and Repay Gas Costs

Aave lending protocol interface on Base and Arbitrum showing supply and borrow transaction costs

Same protocol, totally different gas

Aave is the most-used lending protocol in DeFi — you supply crypto to earn yield and borrow against it. On Ethereum mainnet I never bothered supplying small amounts, because every action cost $15 to $18 in gas and it'd eat months of interest. On Base and Arbitrum those same actions run $0.10 to $0.30. That's the difference between "lending is for whales" and "even a $50 position is worth depositing."

I moved my lending activity off mainnet a while back. Here's what each action actually costs and the break-even I wish I'd known upfront.

Gas per Aave action

On a normal day in 2026, roughly:

All of these swell during mainnet congestion on Arbitrum (the data-fee thing again — the Arbitrum fee explainer covers it). Base stays a bit flatter. But even at peak, we're talking fractions of a dollar. The same supply transaction on mainnet has cost me up to $18. It's not a subtle difference.

The break-even you actually care about

Here's the number people ask me about: how small can a deposit be before gas eats the yield? On mainnet the answer was painful — you needed hundreds of dollars in just to make the gas worthwhile over a year. On L2, do the math: supply plus eventual withdraw is maybe $0.40 in gas total. If you're earning even 3% annual yield on USDC, you need roughly $13 deposited to cover that $0.40 of gas over a year — and that's it.

So a $50 supply absolutely makes sense now. A $20 supply makes sense. The gas simply isn't the barrier anymore. That's genuinely new — it's one of the first times DeFi has been economically rational at pocket-money scale. The live Base tracker lets you confirm the current gas is in its normal cheap band before you start.

Approval plus action, plus interest-bearing versions

Two setup notes. First, like any DeFi app, Aave needs you to approve the token once before supplying — that's the extra one-time transaction. On L2 it's a few cents, but don't be confused by the two prompts.

Second, when you supply, you receive an interest-bearing version of the asset (think aToken-style balance). If you later want to use that supplied position as collateral elsewhere or move it, that's another approval on the interest-bearing token. I've had friends approve USDC, supply, then get surprised when borrowing asks for a second approval — it's normal. Budget one approval per token type you touch. The mechanics are the same across the whole ecosystem; I laid them out in the approval fee guide.

Should you use Base or Arbitrum for lending?

Aave is live on both. My practical rule: go where the asset and the rate are better for you. Gas is so close between them that it's a rounding error on lending actions — maybe a few cents difference per transaction. Base tends to have a slight edge on transaction cost; Arbitrum has deeper liquidity across a wider range of markets and has hosted Aave longer. The yields (APY/APR) vary market by market, so check both rather than assuming one is cheaper to run.

If you're comparing the chains overall, the honest Base vs Arbitrum comparison is what I reference. For a new wallet on either, make sure you have a few dollars of ETH parked for gas — the gas reserve guide recommends $5 to $10, which covers weeks of lending activity.

Before you supply your first dollar

Quick checklist: get the network added to MetaMask (Base or Arbitrum setup), keep $5+ of native ETH on hand for gas, and glance at the Arbitrum calculator or Base calculator so you know you're not transacting during a rare spike. Then supply away. The gas won't be the thing you remember — the yield on amounts that finally make sense will be.

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