0.07 gwei. what an empty mainnet costs
one reading on 7 september 2026 at 23:30 berlin time: a base fee of 0.068 gwei, a transfer for a fraction of a cent, a swap for two or three cents, and ethereum holding 8.7 times the tvl of the next chain.
· berlin · alina schanz
- question
- the cost of a transaction on ethereum mainnet with the base fee near its floor, and the chains that hold the value while the activity moves to the rollups.
- data
- one reading on 7 september 2026 around 23:30 berlin time: the base fee of the next block from a public node, the eth price from coingecko, total value locked by chain from defillama.
- method
- daily_card.py and gas_now.py: gas units times the base fee plus the median tip of the last 20 blocks, times the eth price.
- finding
- at 0.068 gwei a plain transfer cost a fraction of a cent and a swap two or three cents. defillama put 8.7 times as much value on ethereum as on the next chain.
data
python gas_now.py.| eth base fee, next block# | 0.068 gwei |
|---|---|
| eth price# | $2,488 |
| tvl by chain# | ethereum $49.6b · bsc $5.7b · base $5.6b · arbitrum $1.4b |
observations
mainnet blockspace was cheap that night. a transfer takes 21,000 gas and a uniswap swap about 150,000, so at 0.068 gwei and $2,488 an ether the swap cost about two and a half cents before the tip33 from the limits: "the swap figure uses a fixed 150,000 gas.". the week-37 note, a day later, gives the context: over 50,400 blocks the median base fee was 0.071 gwei and the 90th percentile 0.202.
the value stayed on the l1. defillama counts $49.6b on ethereum, 8.7 times bsc at $5.7b, while most transactions happen on the rollups and in blobs. cheap blockspace on the chain with the most value: i want to follow what that does to the fees the l1 collects.
method
python daily_card.py
python gas_now.pyboth scripts live in onchain-notes: python 3.10+, standard library, public endpoints, no key. the base fee comes from eth_feeHistory, whose last entry is the next block. gas_now.py prices four actions: an eth transfer at 21,000 gas, an erc-20 transfer at 65,000, a uniswap swap at 150,000 and an nft mint at 200,000.
sources
- base fee: a public ethereum json-rpc node,
eth_feeHistory. - eth price: coingecko
simple/price. - tvl by chain: defillama
v2/chains, as defillama counts it.
limits
- one reading at one moment. the base fee changes with every block, twelve seconds apart; the weekly notes give the distribution.
- the swap figure uses a fixed 150,000 gas. a real route can take more or less.
- tvl is defillama's number: defillama decides which contracts count and how to price what sits in them. it moves with prices and deposits.
revised 21 sep 2026. i rewrote this note as question, data, method, observations, sources and limits. i took out the btc, sol, dominance and fear & greed readings, a line on sentiment and two news links: they were market commentary, and none of it came from the chain. the base fee, the eth price and the tvl figures are the ones from 7 september. none of it is advice.
revised 23 sep 2026. the links to my code now point to the copies on this site, and short notes in the margin say where a figure came from. the figures and the sentences above did not change.