Median Fee Rate (sat/vB)
Median feerate in sat/vB of confirmed transactions over the last 24 hours - congestion thermometer resistant to outliers. Below 5 sat/vB = light, above 50 = heavy demand for block space.
What is it?
Median Fee Rate measures the median feerate (in sat/vB) of transactions included in confirmed blocks over the last 24 hours. Unlike total or average fees, the median is resistant to outliers (extremely high or near-zero fee transactions). This metric represents the 'typical price' for getting confirmation within a reasonable timeframe. A feerate of 1 sat/vB means virtually no congestion; above 50 sat/vB, congestion is significant and users pay a premium for priority.
How to read
A low median feerate (<5 sat/vB) indicates a light mempool - transactions pass easily. A high median feerate (>20 sat/vB) marks active congestion and competition for block space. Spikes coincide with bull runs, Ordinals inscription waves, and panic events (hacks, liquidations). The 7d MA smooths daily volatility.
Key zones
Median feerate ranges from <1 sat/vB (absolute calm, deep bear) to 200+ sat/vB (extreme congestion). Practical thresholds: <5 sat/vB = no congestion, 5-20 = moderate, 20-100 = high, >100 = extreme. Sub-satoshi regimes (<1 sat/vB) appear during phases of structurally empty mempool (deep bear, post-inscription eras).
What to observe
Watch the correlation with mempool size: swollen mempool + high median feerate = real congestion. Empty mempool + low feerate = underutilised network. Divergences between median and average feerate reveal outlier transactions (a single 1000 sat/vB transaction pulls the mean but not the median).
Historical context
Bitcoin's fee market became competitive when blocks regularly filled (~2016). SegWit (2017) increased effective capacity, temporarily reducing feerates. The Ordinals era (2023) caused the highest median feerates ever observed. Median feerate has become the reference metric for wallets to estimate fees, gradually replacing estimates based on total fees.
Expert notes
Data comes from a full node Bitcoin via the fee_rate_median series (daily median of confirmed transaction feerates). The median is computed across all transactions of the day, weighted per transaction (not per block). Very low feerates (<1 sat/vB) are possible during empty mempool periods thanks to most nodes' minimum relay fee (1 sat/vB), but some transactions go below via custom miners.
Common mistakes to avoid
Confusing median feerate with total fees is the most common error. Median feerate measures the 'unit cost' of a transaction, while total fees also integrate transaction volume. Low feerate + high total fees = many cheap transactions (consolidation). High feerate + moderate total fees = few but expensive transactions (congestion with self-censorship).
Programmatic access
REST API
curl -sS \
'https://api.trinityinsights.io/api/v1/onchain/fee-rate-median/history?days=90' \
-H 'X-API-Key: $TRINITY_API_KEY'MCP server
{
"tool": "get_chart_value",
"metric_id": "fee-rate-median",
"timeframe": "1y"
}Required tier: pro. See the pricing grid for the tier list and the MCP documentation for multi-client configuration.
Related metrics
Institutional disclaimer
Trinity Insights is an educational and analytical tool. The metric above does not constitute investment advice. Trinity Insights is not a Crypto-Asset Service Provider (CASP) registered under MiCA Regulation (EU) 2023/1114. See the full disclaimer.