The five components
- Bridge / route fee. What the winning bridge or route charges. Many routes quote "zero" here and earn inside the rate instead — the fee exists whether you can see it or not.
- Swap-leg fees. If your route includes a swap (ETH → USDC, for example), each DEX leg carries its pool fee, typically 0.01%–0.3% depending on the pool tier.
- Source gas. The network cost of the transaction on the chain you're leaving. This is the most volatile number — an Ethereum mainnet send can cost more than everything else combined during a congestion spike.
- Destination gas. The cost of delivering funds on the arrival chain. Smart routes pre-fund this and deduct it from your received amount, so you don't need the destination's gas token in advance.
- Slippage cost. The gap between the quoted rate and the rate you actually fill at. On quiet pairs it's a rounding error; on thin pools at size it's the biggest line item of all.
Worked example: $1,000 USDC, Ethereum → Base
| Component | Typical Cost | Notes |
|---|---|---|
| Route fee | $0.00 | Competitive corridor — bridges bid at zero to win flow |
| Swap-leg fees | $0.00 | Same token both sides, no swap needed |
| Source gas (Ethereum) | $1.20 – $4.50 | Highly time-of-day dependent |
| Destination gas (Base) | $0.01 – $0.10 | L2 gas is effectively free |
| Slippage cost | $0.10 – $1.00 | Deep USDC liquidity on this corridor |
| All-in | ≈ $1.30 – $5.60 | 0.13% – 0.56% of the transfer |
The same $1,000 moved through a CEX detour (withdrawal fees on both sides, spread on the trading pair) typically costs 0.5%–1.5% plus two waits. The aggregator route wins on cost and time on most corridors — the exception being when mainnet gas is spiking, which is timing, not structure.
When costs spike
- Mainnet congestion. Source gas on Ethereum can 10x during NFT mints, exchange outages or volatile markets. L2-to-L2 routes barely notice.
- Volatile pairs at size. A $50,000 swap through a thin pool moves the price against you. Split the transfer or route through a stablecoin pair.
- Exotic tokens. The deeper the destination liquidity for your token, the cheaper the landing. ETH, USDC and USDT travel at commodity rates; long-tail tokens don't.
How to cut the bill
- Stay off mainnet when you can. Fund Arbitrum or Base directly from your exchange — withdrawals there cost cents.
- Bridge stablecoins, swap after. USDC and USDT have the deepest cross-chain liquidity and the tightest spreads of any asset class.
- Travel off-peak. US evening and Asian morning hours reliably show the lowest Ethereum gas. Weekends are calmer still.
- Batch your transfers. Gas is largely flat regardless of size — one $5,000 bridge costs about the same as five $1,000 ones.
Check any route's live all-in number in the calculator, and see how cost varies by corridor in the route guide.
Last reviewed: September 2026.