A subsidiary of Crescent Electric Supply Company, a US based electric hardware supplier, says they have crunched the numbers to measure how much it would cost to mine one bitcoin across the world. They say:
“South Korea comes in as the most expensive country for mining a single coin at $26,170. From there, Niue, Bahrain, the Solomon Island, and the Cook Islands round out the top five, respectively.
On the flipside, Venezuela came in as the cheapest nation at $531. Their electricity rates are heavily subsidized by the government, leading to incredibly low prices.
Trinidad and Tobago, Uzbekistan, Ukraine, and Myanmar round out the rest of the five least expensive nations.
The United States came in as the 41st cheapest country for mining at $4,758. Russia, a major mining hub, was just a little below the U.S. at $4,675. China came in as the 17th cheapest nation at $3,172.”
How exactly they have undertaken the measurements and whether it is just electricity costs is unclear, with trustnodes receiving no response at the time of writing. They say however:
“For the mining rigs, we used the AntMiner S9, the AntMiner S7, and the Avalon 6. We were able to calculate the numbers on how many days it would take to mine one coin and how much power that would use. Based on the mining difficulty when this study was finalized in early January 2018.”

Interestingly, India is almost as cheap as China, but bitcoin mining has failed to gain much traction there for some reason. Perhaps because India’s climate is somewhat hot, thus needing higher costs in cooling.
The balkans are generally fairly cheap too, leading some to dub the region as Europe’s China, but America is not that expensive either, at just $4,800.
Compared to the current price of one bitcoin, that would be very profitable indeed if it is total cost. One would however need to consider the potential added difficulty, thus the risk that it could become unprofitable.
If, on the other hand, that is not total cost but only electricity cost, then that would be only one aspect of a mining operation, especially if it is a mining farm.
In those instances, there would be land costs, hardware of course, cooling costs, maintenance, employee costs and so on. Which would probably mean, even without difficulty increases, that the current price of around $9,000 would just about break them even with a little bit of profit.
At a price of $6,000, where bitcoin seemingly recently bottomed, they would most probably be at a loss. Something that might be supported by the action of Bitmain’s wallet, which, as the biggest miner, might be more widely representative.
Their gains grew and grew during the bull run last year, even as previously they kept on selling and selling their bitcoins. But afterwords they gradually kept falling to now “just” 4,000 bitcoins (~$35 million).

Estimating the total cost of mining one bitcoin, especially in China, but also across the world, would be a competitive advantage certainly for miners, but also for traders and holders.
That’s because once price goes below that cost, miners would no longer be in profit. So you’d think miners would hold the coins in the hope price rises, unless they’ve given up hope due to some black swan and are trying to salvage all they get.
In normal circumstances, miners taking out that supply would mean a price rise if demand falls by less than supply falls.
Karl Marx calls that the labor value of production, while generally one can call it the cost of production. If the price of a certain thing goes below that cost, then supply would fall until demand is sufficient for the price to be above the cost.
Knowing the total cost, therefore, or the price point where producers reach a profit, can be an easy way to estimate the floor of an asset.