Full Pay-Per-Share (FPPS)

What Is Full Pay-Per-Share (FPPS)?

Full pay-per-share (FPPS) is a mining pool payout method that compensates miners for every valid share of work they submit, paying a fixed rate derived from both the block subsidy and the average transaction fees per block. It extends the original pay-per-share (PPS) model, which only paid miners based on the block subsidy while the pool kept all transaction fee revenue.

As transaction fees have grown to represent a meaningful share of total block rewards, especially after the April 2024 halving reduced the subsidy to 3.125 BTC, the gap between PPS and FPPS payouts has widened. FPPS ensures miners receive their proportional share of the entire theoretical block value, not just the subsidy component.

The tradeoff is straightforward: miners get steady, predictable income, while the pool operator absorbs the variance risk of both block-finding luck and transaction fee fluctuations. In exchange, FPPS pools charge higher fees than variance-exposed models like PPLNS.

How It Works

FPPS builds on the concept of shares: proofs of work that meet a difficulty target lower than the actual Bitcoin network difficulty. A share proves the miner is performing computation, even when that computation does not produce a valid block. The pool sets a per-miner share difficulty based on each miner's hashrate, adjusting it so shares arrive at a consistent rate.

The FPPS Formula

The per-share payout under FPPS is calculated as:

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

Breaking this into components:

1. The pool monitors recent blocks on the Bitcoin network (typically a 144-block lookback window, roughly 24 hours) and calculates the average transaction fees per block
2. Most pools apply outlier filtering: for example, excluding blocks with fees below the 5th percentile and above the 95th percentile to prevent fee spikes from distorting the average
3. The filtered average fee is added to the current block subsidy (3.125 BTC post-halving) to produce a theoretical total reward per block
4. This total reward is divided by the current network difficulty to produce a fixed per-share rate
5. Miners are paid this rate for every valid share they submit, regardless of whether the pool finds any blocks during that period

Payouts are typically settled daily. When difficulty adjustments or halvings occur mid-day, some pools split the day into separate time slots for independent calculation.

Share Difficulty and Scaling

Shares scale linearly with difficulty: one share at difficulty 100 equals 100 shares at difficulty 1. A high-hashrate ASIC miner might submit hashes worth thousands of equivalent shares per submission, while a smaller miner generates fewer. This normalization ensures fair proportional reward regardless of miner size.

The pool sums each miner's shares (weighted by share difficulty) and divides by network difficulty to determine what fraction of the theoretical block reward that miner earned. This fraction multiplied by the FPPS rate produces the miner's payout.

FPPS vs Other Payout Methods

Mining pools use several payout methods, each with different tradeoffs between predictability, fees, and risk allocation. Understanding these differences is critical for miners choosing a pool.

PPS: Subsidy Only

Basic PPS was the original fixed-rate model. It pays miners a fixed amount per share based solely on the block subsidy divided by network difficulty. The pool retains all transaction fee revenue. When fees were negligible compared to the subsidy, this worked well. As fees have grown (sometimes exceeding 5-10% of total block value), PPS miners leave significant revenue on the table.

PPS+: Hybrid Approach

PPS+ splits the payout into two components: the block subsidy is paid as a fixed per-share rate (like PPS), while transaction fees are distributed only from blocks the pool actually finds, proportional to contributed shares (like PPLNS). This gives subsidy predictability with fee upside during lucky periods, but also means fee income drops during unlucky streaks. ViaBTC is a prominent pool using PPS+.

PPLNS: Pay Per Last N Shares

PPLNS pays miners only when the pool finds a block, distributing the full reward (subsidy plus actual transaction fees) among miners who contributed shares within a recent window. This exposes miners to block-finding luck variance: long stretches without blocks mean no income. PPLNS charges lower fees (typically 0-2%) because the pool bears no financial risk.

Why FPPS Dominates

FPPS has become the most widely adopted payout method among major Bitcoin mining pools. Foundry USA (the largest pool by hashrate), AntPool, F2Pool, Braiins Pool, Luxor, and Binance Pool all offer FPPS or close variants. Several factors drive this dominance:

• Revenue predictability: miners can forecast income precisely, which matters for operations with fixed costs like electricity, hosting, and equipment financing
• Institutional demand: large-scale mining operations and publicly traded miners need predictable cash flows for financial reporting and investor relations
• Full fee capture: unlike PPS, FPPS ensures miners receive their share of transaction fee revenue, which becomes increasingly important as block subsidies decrease with each halving
• Simplified accounting: a fixed daily payout simplifies tax reporting and business planning compared to the variable income of PPLNS

Braiins Pool (formerly Slush Pool, the first-ever Bitcoin mining pool) exemplified this trend when it transitioned from its proprietary "Scoring" payout system to FPPS in late 2023, citing market demand for predictable earnings.

Use Cases

Institutional Mining Operations

Large-scale mining farms with significant capital expenditures prefer FPPS because it converts volatile mining rewards into a steady revenue stream. This predictability is essential for securing financing, managing operational costs, and meeting investor expectations. Publicly traded miners often require the financial certainty that FPPS provides for their quarterly reporting.

Small and Medium Miners

Individual miners and smaller operations benefit from FPPS because it eliminates the frustration of luck-based variance. A miner contributing a tiny fraction of pool hashrate would experience extreme payout swings under PPLNS: potentially days without income followed by windfalls. FPPS smooths this into consistent daily payments proportional to contributed work.

Post-Halving Mining Economics

After the April 2024 halving, the block subsidy dropped to 3.125 BTC, making transaction fees a proportionally larger share of total mining revenue. FPPS ensures miners capture this fee revenue predictably. Under basic PPS, miners would forfeit an increasingly significant portion of their theoretical earnings. For deeper analysis of mining economics, see the mining pool payout method comparison.

Risks and Considerations

Pool Operator Counterparty Risk

Under FPPS, the pool operator must pay miners whether or not the pool finds blocks. During extended unlucky streaks, the pool pays out more than it earns, drawing on financial reserves. If a pool becomes insolvent, miners lose unpaid earnings. This counterparty risk is inherent to any custodial payout model: miners trust that the pool has sufficient reserves to honor its commitments.

Fee Spike Revenue Loss

FPPS pays miners based on the historical average of transaction fees, not actual fees from blocks the pool mines. During fee spikes (such as those caused by Ordinals or Runes activity), the pool collects the elevated actual fees while paying miners the lower historical average. This asymmetry means FPPS miners systematically miss out on windfall fee events. Conversely, during low-fee periods, the pool pays more than it earns, partially offsetting this effect over time.

Opaque Fee Estimation

Most pools do not fully disclose their FPPS calculation methodology. While the general approach (144-block lookback with outlier filtering) is consistent across the industry, the exact filtering parameters, weighting, and update frequency vary by pool and are often not published. Miners must trust that the pool's fee estimation is fair. Some pools like Luxor and Braiins have published their exact formulas, but this level of transparency is not universal.

Higher Pool Fees

FPPS pools typically charge 2-4% in fees, compared to 0-2% for PPLNS pools. This premium reflects the insurance cost of absorbing variance risk. Large institutional miners can negotiate lower rates (some pools offer 0% for high-volume clients), but retail miners generally pay the standard fee. The fee partially offsets the benefit of receiving transaction fee revenue.

Centralization Pressure

Because FPPS requires pools to maintain substantial financial reserves to cover variance, it favors well-capitalized operators. This creates a barrier to entry for smaller pools and contributes to mining pool centralization. Non-custodial alternatives like OCEAN's TIDES system attempt to address this by embedding payouts directly in coinbase transactions, removing the need for pool reserves entirely.

FPPS Calculation Example

To illustrate how FPPS payouts work in practice:

Block subsidy:            3.125 BTC
Avg transaction fees:     0.25 BTC  (from 144-block lookback)
Theoretical block value:  3.375 BTC
Network difficulty:       148,000,000,000,000

Per-share value (at share difficulty 1):
  3.375 / 148,000,000,000,000 = 0.0000000000228 BTC

Miner contributing 100 TH/s for 24 hours:
  Expected shares ≈ 100,000,000,000,000 × 86,400 / (2^32)
  Daily payout ≈ shares × per-share value
  (minus pool fee of 2-4%)

The miner receives this payout regardless of whether the pool found any blocks that day. The pool smooths out block-finding luck across all miners and across time.

The Future of FPPS

As block subsidies continue to halve approximately every four years, transaction fees will become an increasingly volatile and significant portion of total mining revenue. This trend has two competing implications for FPPS:

• Demand increases because miners want fee exposure without variance, making FPPS more valuable as an insurance product
• Risk increases for pool operators because fee volatility is harder to estimate than the fixed, known block subsidy, potentially driving up FPPS fees over time

The tension between miner demand for predictability and pool operator risk tolerance will shape how FPPS evolves. For a broader view of how mining profitability is affected by payout method choice, see the research on Bitcoin mining economics.

This glossary entry is for informational purposes only and does not constitute financial or investment advice. Always do your own research before using any protocol or technology.