Full pay-per-share (FPPS) is a payout method used by a mining pool in which miners receive a fixed amount for every valid share they submit, covering both the block subsidy and an estimate of the transaction fees a block would earn. Like plain pay-per-share (PPS), it pays whether or not the pool finds a block. The "full" refers to the fee component, which plain PPS leaves with the pool.
FPPS is the standard method at several of the largest Bitcoin (BTC) pools; Foundry USA, for example, states that it pays members on an FPPS basis. It sits between plain PPS and pay-per-last N shares (PPLNS): miners get PPS-style certainty but, like PPLNS miners, share in fee income.
Imagine a waiter on a fixed hourly wage who also receives an average tip per hour, whether or not that evening's diners tipped well. The restaurant pays the same amount every hour and keeps any difference between the real tips and the average. Plain PPS is the wage without the tips; FPPS is the wage plus the estimated tips.
For miners, the tips are the fees that users attach to transactions. In busy periods they can add a noticeable amount on top of the fixed block subsidy, and FPPS makes sure miners see part of that.
Formula and example
Under FPPS the payment per difficulty-1 share is:
- is the amount credited for one difficulty-1 share.
- is the pool fee as a decimal.
- is the block subsidy, the newly issued part of the block reward.
- is the average transaction fee per block over the pool's reference period.
- is the network's mining difficulty, which equals the expected number of difficulty-1 shares per block.
Worked example: a miner hashes at 200 TH/s, which at an illustrative difficulty of 100 trillion is expected to produce about 0.0000402 of a block per day. With a subsidy of 3.125 BTC, an assumed average fee of 0.05 BTC per block and a 2% pool fee, daily pay is , or about 0.0001252 BTC. Under plain PPS with the same fee the miner would receive about 0.0001232 BTC, so the fee component adds roughly 2,000 satoshis a day in this example.
How pools estimate fees
The fee term is the part of FPPS that varies between pools. Common approaches include averaging the fees in all network blocks over the previous day or over a fixed number of recent blocks, or calculating a fee ratio over the same period and applying it to the subsidy. Pools publish their method, and miners compare them because the choice matters when fees swing. Fee spikes occur when the mempool fills up, for example during the 2023 and 2024 waves of Ordinals inscriptions and Runes token launches on Bitcoin, when fees for some blocks briefly rivalled or exceeded the subsidy.
Because FPPS pays an average, a sudden fee spike benefits the pool for a short time, and a sudden fall benefits miners until the average catches up. Some pools settle the fee component after the fact for each day, which narrows the gap between estimated and actual fees.
Who carries the risk
Under FPPS the pool absorbs both block-finding luck and fee uncertainty. It pays out a fixed expected value on every share while receiving variable income, so it needs reserves and charges fees that have typically been higher than for PPLNS, often around 2% to 4% depending on the pool and the miner's size. In return, miners get daily payments that move only with network difficulty, hashrate and average fees, which suits industrial miners who finance machines and electricity contracts and need predictable cash flow.
Criticism and alternatives
FPPS has been criticised on several grounds:
- Concentration. Only large, well-capitalised pools can afford to absorb FPPS variance, which pushes hashrate towards a few operators and lowers a network's Nakamoto coefficient.
- Opacity. Miners are paid on a formula rather than on actual blocks, so they depend on the pool's honesty about blocks found and fees earned.
- Block-template control. In most FPPS pools the operator, not the individual miner, chooses which transactions enter a block, which critics see as a point of potential centralisation and censorship.
Alternatives include PPLNS and its variants, solo mining for those who can bear the variance, and newer pool designs that let miners build their own block templates. Like all pool methods, FPPS applies only to proof-of-work coins; in proof-of-stake systems the comparable arrangement is a staking pool. For a broader view of the mining business, see crypto mining and mining rig.