Calculator Accuracy & Methodology
Every figure published on pro.startmining.io is computed from a self-hosted Bitcoin Core full node — no third-party blockchain API. As of July 17, 2026, the difficulty read by our node matches the independent public reference (mempool.space) exactly, and our hashprice differs from it by 2.5%. This page documents the sources, the formulas, and their limits.
Data sources
- Blockchain state — difficulty, block height, mempool, fees: read directly from our Bitcoin Core full node. These are consensus data, exact by construction — not estimates.
- Network hashrate: it cannot be measured, only estimated — from the pace of the last 144 blocks (~24 h) against current difficulty. Two different estimation windows give two different values; that is expected (see the cross-check).
- BTC price: aggregated public exchange data, normalized to USD.
- ASIC catalog: 88 models from manufacturer datasheets; market price index by efficiency band (indicative).
- History: daily series since 2009, derived from the blockchain itself.
Formulas — open and executable
The simulator’s formulas are public and, more importantly, executable: every response from our calculation API details the steps applied to current data, so it can be audited or quoted as-is.
- 1. Efficiency (J/TH) = power (W) ÷ hashrate (TH/s)
- 2. Daily energy (kWh/day) = power (W) ÷ 1,000 × 24 h
- 3. Electricity cost ($/day) = energy (kWh/day) × rate ($/kWh)
- 4. Gross revenue ($/day) = hashrate (PH/s) × hashprice ($/PH/day)
- 5. Pool fee ($/day) = gross revenue × fee rate (2% default)
- 6. Net profit ($/day) = gross revenue − pool fee − electricity cost
- 7. Breakeven electricity ($/kWh) = (gross revenue − pool fee) ÷ daily energy
Monthly figures use 730 h/month (30.4167 days), never 30 days. Executable reference: GET /api/calculate (documented in the OpenAPI spec)
Live accuracy cross-check
As of July 17, 2026, comparing our node against an independent public source (mempool.space):
| Metric | Our node | Independent reference | Delta |
|---|---|---|---|
| Difficulty | 127.17 T | 127.17 T | exact match |
| Hashprice ($/PH/day) | 31.26 | 32.06 | 2.5% |
| BTC price (USD) | 62,728 | 62,811 | 0.1% |
| Estimated hashrate (EH/s) | 787 | 894 | 11.9% |
Difficulty is identical by construction: both sources read the same blockchain.
The hashrate gap comes from estimation windows: we average over ~24 h (144 blocks), the reference over 1 week. Neither value is “wrong” — hashrate is an estimate by nature.
Worked example, computed live
Antminer S21 XP at $0.06/kWh, 2% pool fee, network data as of July 17, 2026:
| # | Step | Numeric application |
|---|---|---|
| 1 | ASIC efficiency | 3645 / 270 = 13.5 J/TH |
| 2 | Daily energy consumption | 3645 / 1000 x 24 = 87.48 kWh/day |
| 3 | Daily electricity cost | 87.48 x 0.06 = $5.25/day |
| 4 | Daily gross revenue | 0.27 x 31.26 = $8.44/day |
| 5 | Pool fee | 8.44 x 0.02 = $0.17/day |
| 6 | Daily net profit | 8.44 - 0.17 - 5.25 = $3.02/day |
| 7 | Breakeven electricity price | (8.44 - 0.17) / 87.48 = $0.0946/kWh |
Result: +$3.02/day net profit (35.8% margin), breakeven electricity at $0.0946/kWh.
The same calculation, with the same steps, is available for any ASIC through the API — or interactively in the calculator. Open the calculator
What this calculator does not claim to do
- It computes an expected revenue at constant conditions. An FPPS pool pays that expectation (minus its fee); solo mining is dominated by variance (“luck”) in the short run.
- Difficulty historically grows: any static figure goes stale. To project over months, use the backtest (real 2009-to-today data) and Monte Carlo (10,000 trajectories).
- Displayed ASIC prices are market estimates by efficiency band — indicative, not quotes.
- Out of scope: taxes, hosting costs beyond electricity, cooling overhead, downtime.
Frequently asked questions
How accurate is this Bitcoin mining profitability calculator?+
Consensus data (difficulty, blocks, fees) are read directly from our Bitcoin Core full node: they are exact by construction — as of July 17, 2026, our difficulty matches the independent mempool.space reference exactly. Hashprice, which derives from it, differs by 2.5%. The output is an expected revenue: an FPPS pool pays that expectation, minus its fee.
Where does the mining data come from?+
From a Bitcoin Core full node self-hosted by Startmining — no third-party blockchain API in the chain. The BTC price is aggregated from public exchange data; ASIC specs come from manufacturer datasheets.
Why do mining calculators give different results?+
Three causes dominate: the hashprice source (transaction-fee estimation, BTC price source), the hashrate estimation window (24 h vs 1 week), and defaults (pool fee, uptime). Our calculation steps are auditable one by one via GET /api/calculate, which makes any divergence traceable.
How often is the data updated?+
Network dashboard: every 30 seconds. Public APIs: 1-5 minute cache. SSR snapshots: hourly. Historical series: daily.