Pay-Per-Share (PPS)

Pay-per-share is a mining pool payout method that pays miners a fixed reward for each valid share submitted, regardless of whether the pool finds a block.

Key Takeaways

Pay-per-share (PPS) pays miners a fixed amount for every valid share submitted to a mining pool, regardless of whether the pool actually discovers a block. This provides steady, predictable income.
PPS shifts all variance risk from miners to the pool operator, who must maintain reserves to pay miners even during unlucky streaks. In exchange, PPS pools charge higher fees (typically 2 to 4%) compared to other payout models.
Three variants exist: pure PPS (block subsidy only), PPS+ (subsidy via PPS plus transaction fees via PPLNS), and FPPS (Full PPS, which includes estimated transaction fees in the per-share calculation). FPPS is the dominant model among major pools today.

Pay-per-share (PPS) is a mining pool payout method that guarantees miners a fixed reward for each valid share they submit. A share is a proof of work that meets a lower difficulty target set by the pool, rather than the full network difficulty required to produce an actual block. Shares serve as verifiable evidence that a miner is contributing computational work.

Under PPS, miners earn based on statistical expectation rather than actual outcomes. Whether the pool finds zero blocks or ten blocks in a day, each miner receives the same payout per share. This makes PPS function like a wage: consistent and predictable, with the pool operator absorbing all the luck-based variance inherent to Bitcoin mining.

PPS was introduced to solve the fundamental income volatility problem in mining. Solo miners and miners in proportional pools experience highly irregular payouts: long dry spells followed by occasional windfalls. For miners who depend on regular cash flow to cover electricity and hardware costs, this variance is a serious operational risk. PPS eliminates it.

How It Works

The per-share payment is calculated from two values: the current block subsidy (3.125 BTC since the April 2024 halving) and the network difficulty.

The PPS Formula

The value of each share is derived from the expected reward per unit of work:

PPS Share Value = (Block Reward / Network Difficulty) × Share Difficulty

Example with simplified numbers:
  Block Reward    = 3.125 BTC
  Network Difficulty = 125,000,000,000,000 (≈125 trillion)
  Share Difficulty   = 1,000,000

  Share Value = (3.125 / 125,000,000,000,000) × 1,000,000
             = 0.000000025 BTC per share

In practice, a miner's assigned share difficulty is adjusted dynamically by the pool based on the miner's hashrate. Higher-hashrate miners receive a higher share difficulty so that shares arrive at a manageable rate (roughly every few seconds). A share at difficulty 1,000,000 counts as 1,000,000 base-difficulty shares, so the payout scales proportionally.

The pool assigns each miner a share difficulty target based on their hashrate
The miner performs hashing operations, looking for outputs below the share difficulty target
When the miner finds a valid hash below the share target, they submit it to the pool as a share
The pool verifies the share is valid and credits the miner at the fixed per-share rate
If the share also happens to meet the full network difficulty target, it becomes a valid block solution

On average, one difficulty-1 share is found for approximately every 4.295 billion hashes (2^32). The network difficulty determines how many shares, on average, the entire network must produce before one of them qualifies as a valid block.

PPS Variants

As transaction fees have grown in importance relative to the block subsidy, the original PPS model has evolved into several variants that differ in how they handle fee revenue.

Pure PPS

The original model calculates per-share value using only the block subsidy (currently 3.125 BTC). All transaction fees collected from blocks the pool mines are retained by the pool operator. This is rarely offered today because it leaves miners without a share of transaction fee revenue, which can represent 5 to 15% or more of total block value.

FPPS extends the PPS formula to include an estimate of average transaction fees:

FPPS Share Value = (Block Subsidy + Avg Transaction Fees) / Network Difficulty × Share Difficulty

The pool estimates average transaction fees over a recent window (typically 24 hours of observed coinbase revenue across the network) and includes that estimate in every share payment. The pool absorbs variance on both the block subsidy and transaction fees. FPPS is the dominant payout model among major pools today, including Foundry USA, AntPool, F2Pool, and Binance Pool.

PPS+

PPS+ is a hybrid that splits the two revenue components between different payout methods:

Block subsidy: paid using PPS (fixed per share, guaranteed)
Transaction fees: distributed using PPLNS (variable, based on actual blocks found and the miner's proportional share contribution)

This gives miners the stability of PPS for the predictable subsidy portion while allowing upside from transaction fees when the pool has good luck. Pools like ViaBTC and F2Pool offer PPS+ alongside their FPPS options.

Comparison With Other Payout Models

Understanding PPS requires context on how it compares to alternative payout schemes used by mining pools.

Feature	PPS / FPPS	PPLNS	PROP	SOLO
Payout trigger	Every valid share	Only when pool finds a block	Only when pool finds a block	Only when miner finds a block
Miner variance	Near zero	Medium	High	Extremely high
Risk bearer	Pool operator	Miners	Miners	Miner alone
Typical fees	2 to 4%	0 to 2%	0 to 2%	0 to 2%
Pool hopping resistance	Immune	Strong	Vulnerable	N/A
Best suited for	Steady income, operational miners	Loyal, high-uptime miners	Simple setups (rare today)	Very large hashrate operations

PPLNS (Pay Per Last N Shares) distributes block rewards proportionally among miners based on shares contributed within a sliding window (often set to two times the network difficulty). It only pays when the pool actually finds a block, resulting in lower fees but higher income variance. PPLNS naturally discourages pool hopping because recent shares count more than older ones.

PROP (Proportional) divides each block reward among all miners who contributed shares during that specific round. It is simple but vulnerable to pool hopping, where miners join during the end of a round to collect a disproportionate share. Few major pools use this model today.

SOLO mining connects to a pool for infrastructure but the miner keeps the entire block reward if their work produces a valid block. Variance is extreme: a small miner may wait months or years between payouts.

Why It Matters

PPS has become the backbone of professional Bitcoin mining because it transforms an inherently probabilistic activity into a predictable revenue stream. This has several important implications.

For individual miners and mining businesses, PPS enables financial planning. Electricity contracts, equipment financing, and operational budgets all require predictable cash flow. A miner earning via PPLNS might receive nothing for days during an unlucky streak, creating real cash flow challenges. PPS eliminates this by paying for every share, every day.

For the mining industry more broadly, the dominance of FPPS has contributed to pool consolidation. Because PPS pools must maintain large reserves to cover payouts during bad luck periods, operating a PPS pool requires significant capital. This creates a structural advantage for larger pools, which is one reason pools like Foundry USA and AntPool command substantial portions of the network's total hashrate.

The growing significance of transaction fees after each halving makes the choice between PPS variants increasingly consequential. As the block subsidy decreases (from 3.125 BTC now to 1.5625 BTC at the next halving around 2028), transaction fees represent a larger percentage of total mining revenue. Miners using pure PPS leave this growing revenue share on the table, which is why FPPS and PPS+ have become the standard.

Risks and Considerations

Pool Operator Solvency

The core risk of PPS falls on the pool operator. During extended unlucky streaks where the pool finds fewer blocks than expected, the pool must still pay miners for every share submitted. If reserves are insufficient, the pool faces insolvency. Academic research on mining pool economics confirms that maintaining a low probability of bankruptcy requires substantial capital reserves, and that PPS-style payout schemes "must go hand in hand with a proper capital allocation strategy to avoid ruin."

Higher Fees

PPS pools typically charge 2 to 4% fees compared to 0 to 2% for PPLNS pools. This fee premium is the cost of stable income: over a full year, the fee difference can amount to 5 to 15% less total revenue compared to what a consistently online PPLNS miner would earn under average luck conditions. Miners must weigh the value of predictability against this cost.

Transaction Fee Estimation Risk (FPPS)

Under FPPS, the pool estimates average transaction fees and includes them in per-share payouts. If actual fees collected by the pool fall below the estimated average (due to the pool finding blocks during low-fee periods), the pool loses money on the difference. Conversely, if the pool captures blocks with unusually high fees, it profits. This introduces a secondary variance dimension beyond block discovery luck.

Centralization Pressure

The capital requirements for running a PPS pool create barriers to entry that favor large, well-funded operators. This dynamic has contributed to mining pool concentration, where a small number of pools control the majority of network hashrate. While miners retain control of their own hardware and can switch pools freely, the economic incentives of PPS push toward fewer, larger pool operators. Pool decentralization efforts like the Stratum V2 protocol aim to address some of these concerns by giving miners more control over block template construction, regardless of which pool they mine with.

Pool Hopping Is Not a Concern

Unlike proportional payout models, PPS is immune to pool hopping attacks. Since each share pays a fixed amount regardless of round progress, there is no strategic advantage to joining a pool at a specific point in its mining round. This makes PPS the fairest model from a game-theoretic perspective.