Canon
The Monad gas sheet: a worked bill for a transfer, an approval, and a swap
The gas-pricing page gives the rule. It does not give the three transactions a desk actually signs, in MON, at a stated base fee, with the limit and the used gas kept apart. This is that sheet.
MONAF Blog · 27 October 2026 · 26 min
Monad bills the gas a transaction used, not the gas it asked permission to use, and it prices that gas from the base fee plus the priority tip. The rule is the same shape Ethereum users know. The numbers are not. The current-facts page gives three anchors as illustrations, not as a quote you can paste into a router for the rest of the year. A native MON transfer is 21,000 gas. An ERC-20 transfer is on the order of 65,000. A typical DEX swap is on the order of 200,000. At a 100 gwei base fee, which is 100 times 10^−9 MON per gas, those are 0.0021 MON, 0.0065 MON, and 0.02 MON, before any tip. If the base fee is higher when you arrive, multiply again. Do not multiply by a dollar figure copied from a doc aside. The doc’s own aside, about five hundredths of a cent for a transfer at that floor, goes stale the hour MON moves. The MON figure does not.
Limit and used are different coins in your head
The limit is what the wallet must be able to pay if the call is expensive. The used figure on the receipt is what left your address. A sell this desk signs from a wallet carries a limit of 350,000 gas. At 100 gwei that ceiling is 0.035 MON. The swap will not use all of it. A vault sell carries 550,000, a ceiling of 0.055 MON, because the vault does extra work around the router call. An approval carries 80,000, a ceiling of 0.008 MON. People who add the ceilings and call the sum the round trip are describing a worst case, not a bill. People who ignore the ceilings and keep 0.001 MON for gas are describing a wish. The receipt is the bill. The ceiling is the float you must hold.
Work a 50 MON round trip at the floor, and then say what you do not know. Entry and exit, if each uses 200,000 gas at 100 gwei, cost 0.04 MON together. A 500-tier pool takes 0.05 percent each way, which is 0.025 MON on the way in and about the same on the way out, 0.05 MON, taken in the swap rather than in gas. The fixed cost is near 0.09 MON before the price has moved. A 1.6 percent target on 50 MON is 0.80 MON. The bill is about a ninth of the target. The same bill on a 10 MON clip with a 0.16 MON target is a third of the target before slippage. That is why the size page tells you to convert the percent into MON before you tap. The gas page on the official site cannot say this, because it does not know your target. You do.
Hold the ceiling. Pay the receipt. Compare both with the target, in MON, before the market has done any work.
An approval is a transaction, and it is not free
The first time a token is sold through the router, the token’s approve function must land before the router’s transferFrom. That is a second transaction, its own gas, its own hash. On this desk it is broadcast, then the allowance is read until it is at least the quantity, then the sell is signed. Skipping the wait, because the chain is fast, is how the sell reverts with a transfer error and the wallet says the transaction failed for 0 MON. The approval itself did not fail. It had not been observed yet. Later sells of the same token skip it. If you revoke the approval in the token’s own interface, the next sell is a first sell again.
Where the official page stops
The gas-pricing page will not tell you that a revert still costs the gas used up to the revert, and that a revert is therefore not a free way to “try” a close. It will not tell you that a simulation, eth_call, is free of gas and is the right place to discover a floor the pool will refuse. It will not tell you that a wallet which multiplies the estimate by two, and then multiplies again for a buffer, can refuse to sign because it thinks you cannot pay a ceiling you could have paid easily. Read the limit the desk asked for. 350,000 at the current base fee is a MON amount you can compute in your head: gas times gwei times 10^−9. If the wallet’s prompt is several times that, the wallet has changed the limit. That is a different transaction from the one this page priced.
A sheet you can copy
Write four lines. Base fee, from the latest block, in gwei. Limit the screen is asking, in gas. Product, which is the ceiling in MON. Receipt, filled in after, which is used times the effective price. Do this once for an approval and once for a sell. Add the pool fee in MON, both ways, from the tier and the clip. Subtract the sum from the target in MON. If the remainder is negative, the trade loses if the price does nothing. That is allowed. It is not a surprise, and it should not be discovered from a red card.