Bitcoin Fee Estimator

Real-time mempool fee estimates. Pick a target confirmation window — we'll tell you the right sat/vB.

Calculate cost for your TX

Typical: 140 vB (1-in 1-out SegWit) · 250 vB (1-in 2-out) · 400+ vB (multi-input)

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@ ? sat/vB × 140 vB

Live Bitcoin fee estimator

See the live recommended sat per virtual byte rates for next block, half hour, hour, and economy confirmations. Estimates are pulled from real mempool data, not stale percentile heuristics.

On this page
  1. 1.How the estimates are calculated
  2. 2.Pick the right tier for your use case
  3. 3.Calculate your TX cost
  4. 4.FAQ

How the estimates are calculated

We poll mempool.space every 10 seconds for the recommended fee tiers. These tiers are derived from actual block templates being assembled by mining pools right now, not from a moving average.

Pick the right tier for your use case

Use next block (about 10 minutes) for time-sensitive payments. Use half hour for normal sends. Use hour or economy when you can wait. Most underestimated fee disasters happen when wallets default to economy during fee spikes without warning the user.

Calculate your TX cost

The cost calculator multiplies the live fee rate by your transaction's virtual size. A 1-input 1-output SegWit send is around 140 vBytes. A typical 1-input 2-output send is 250 vBytes. Multi-input consolidations can run 400 vBytes or more.

FAQ

Why does my wallet show different fees?

Wallets use their own algorithms, often more conservative or out of date. Cross-check here before sending.

What is sat per vByte?

It is the amount of sats you pay per virtual byte of transaction data. Higher means faster confirmation.

Can fees ever be too high?

Yes. During fee spikes economic users should wait. Our estimator shows the economy tier for exactly this reason.

Do you support Lightning fees?

Lightning Network fees are off-chain and per-channel. This estimator is for on-chain Bitcoin transactions only.