Workspace / Research tools
Live research

Compare Bitcoin fee priorities with the observed queue

Combine a transaction-size estimate with provider fee recommendations, then inspect the observed mempool backlog and fee bands. All values load only when you request a snapshot.

Explicit assumptionsFormula & methodology includedNo account required

Enable JavaScript to load the named public providers automatically. You can pause the feeds at any time.

Estimate fees from virtual size, not transferred value

Enter the estimated virtual size of your transaction in vbytes. Each fee estimate is the provider's sat/vB recommendation multiplied by your chosen virtual size, rounded up to whole satoshis. Dividing that result by 100,000,000 converts the estimate to BTC.

For example, an illustrative 141 vB transaction at 8 sat/vB costs an estimated 1,128 satoshis. The amount of BTC sent is not part of this multiplication. Inputs, outputs and script types influence virtual size, so a wallet's actual transaction estimate is preferable to an assumed size.

A fee queue is an observation, not a promise

The backlog summary reports transactions, virtual bytes and total attached fees observed by the provider's node. The histogram shows the first returned fee bands and cumulative virtual bytes in the displayed higher-fee bands. Different nodes can hold different unconfirmed transactions.

Fee recommendations and time labels are estimates. New transactions can arrive, miners can choose different sets, and your transaction may have additional constraints. This tool does not construct, sign or broadcast a transaction. It helps compare cost assumptions while leaving execution to your wallet.

Sources and further reading

mempool.space: REST API fee and backlog documentation ↗Esplora: mempool count, virtual size and histogram format ↗

Your research workspace

Save selected inputs and research notes explicitly in this browser. Compare assumptions and restore a saved setup without submitting a trade. JavaScript enables the controls.

Find a tool or explanation