Difficulty

What is Difficulty?

Difficulty is a measure of how hard it is to find a valid Bitcoin block. It is expressed as a number that represents the ratio of the easiest possible target to the current target. A higher difficulty means miners must perform more hash computations on average before finding a valid block.

How Difficulty Works

Bitcoin mining requires finding a hash output that is below a specific target value. The difficulty number tells you how many times harder the current target is compared to the easiest possible target. When difficulty doubles, miners need to perform roughly twice as many hashes on average to find a block.

The current Bitcoin difficulty is in the trillions, meaning it is trillions of times harder to find a block today compared to when Bitcoin launched in 2009 with a difficulty of 1.

Difficulty and Mining Revenue

Difficulty directly impacts mining profitability. The relationship is inverse: when difficulty rises, each TH/s of hashrate produces less BTC per day. Miners track the metric BTC per TH/s per day (sometimes called "hashprice") to understand their revenue efficiency.

For example, if difficulty increases by 5%, your daily BTC earnings decrease by approximately 5%, assuming network hashrate remains constant. This is why difficulty adjustments are one of the most closely watched events in the mining industry.

Historical Growth

Bitcoin's difficulty has grown exponentially over its lifetime, driven by advances in mining hardware from CPUs to GPUs, FPGAs, and modern ASICs. Each generation of hardware dramatically increased total network hashrate, which in turn drove difficulty higher.

Despite this relentless growth, mining remains profitable for operators with access to efficient hardware and low-cost electricity. The difficulty adjustment mechanism ensures that blocks continue to be found approximately every 10 minutes regardless of how much hashrate joins or leaves the network.