Can we say that gas is the unit of transaction fee ?

And gas price is the same transaction fee ?

If so, why we do not use ether and wei instead of gas ?

up vote 7 down vote accepted

in a nutshell :

gas is the cost unit

gas price is a single gas unit's price


Fee= gas*gas price

why using gas instead wei?

because we need a fixed value (unit) for expressing the operations cost. then this initial cost is "translated" in wei/ether which may vary according to the market.

"y operation"= x gas => x gas * market gas price= your fee (Z).

so "y operation" cost will be always x gas, today as in next year, but z will change as the gas price will change.

  • Thank you for your complete and clear answer. However, in my opinion it is still possible to use ether and market ether price instead of gas and market gas price. ex. tx fee = n gas when gas price = m is equivalent of tx fee = a ether when ether price = b USD. maybe I do not consider somethings .... – sas Jul 18 at 12:27
  • 1
    The Vm doesn't know whether the ether price goes up or down. it knows only that a given operation costs a given amount of a fictive unit gas and it let us decide in the market what this unit price according to ether fluctuation. – Badr Bellaj Jul 18 at 12:28

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