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Bitcoin Transaction Fee Estimator

What you should pay right now to get a Bitcoin transaction confirmed, in sat/vB and in dollars.

Example rates — live fees load automatically mempool.space

Current fee to send this transaction

$0.24

at Average speed

Native SegWit · 1 input · 2 outputs · 141 vB

Reference figures for the transaction

Fee rate 2 satoshis per virtual byte
Transaction size 141 virtual bytes — the size unit Bitcoin charges by
Total fee 282 sats

Fee rates from mempool.space, refreshed every 60 seconds while the tab is open. BTC price from CoinGecko, with the last bundled daily close used before the live price loads. Transaction sizes are computed for single-signature spends.

A fee rate is a bid, not a guarantee — even the fastest tier can miss the next block if a wave of higher-paying transactions arrives first. Confirmation times are estimates from current mempool conditions and can change as new transactions arrive.

Every calculator here runs on formulas verified against primary sources and is reviewed before it ships.
Learn about our methodology →
Fabio Arcieri Built and reviewed by
Fabio Arcieri

Last reviewed: September 2026

How bitcoin transaction fees are calculated

Fee (sats) = feerate (sat/vB) x vsize (vB). The feerate is what you bid per unit of transaction size, and vsize is a weight-adjusted byte count that discounts the witness data SegWit and Taproot transactions carry.

The bitcoin amount you’re sending never enters that calculation. A transfer of 0.001 BTC and one of 10 BTC pay the same fee when they share the same size and feerate. The network prices the space a transaction occupies in a block, not the value it carries.

The relationship between bitcoin address type and fees

Address type sets your transaction’s vsize, the only lever in the fee formula you control, and it swings the byte count of a typical one-input, two-output send like this:

  • Legacy (addresses starting with 1 or 3) — 226 vB, the largest of the three because signature data sits in the base transaction instead of a discounted witness section.
  • Native SegWit (bc1q addresses) — 141 vB, 38% smaller than Legacy, because SegWit moves signatures into a witness section that counts at a quarter the weight.
  • Taproot (bc1p addresses) — 154 vB, 32% smaller than Legacy, trading a larger single signature for simpler, more private spending conditions.

Why fees rise and fall

Mempool congestion, the current backlog of unconfirmed transactions visible on mempool.space, drives every feerate swing. There’s no fixed schedule behind the number the widget shows.

When more transactions arrive than the network’s 10-minute block cadence can absorb, the backlog grows and everyone bidding for the next block raises their feerate to outbid the rest. When the backlog clears, competition eases and the feerate falls back toward the network’s floor.

Tips for cheaper transactions

Three levers change what you pay, all verifiable in the widget above:

  • Choose Native SegWit or Taproot addresses — both produce a smaller vsize than Legacy for the same input and output count, which lowers the fee at any feerate.
  • Batch multiple payments into one transaction — combining several outputs into a single transaction spreads overhead bytes across all of them, instead of paying overhead once per send.
  • Time sends around visible mempool congestion — a send during a quiet mempool clears at a lower feerate than the same send during a backlog.

Frequently asked questions

  • What is sat/vB?
    Sat/vB (satoshis per virtual byte) is the feerate unit Bitcoin wallets and block explorers quote: how many satoshis you're bidding for each vByte of your transaction's virtual size (vsize). Multiplying sat/vB by your transaction's vsize gives the total fee in sats. A rate of 20 sat/vB on a 141-vB transaction costs 2,820 sats, convertible to dollars or bitcoin with the [sats converter](/bitcoin-sats-converter/).
  • Does the bitcoin amount you're sending affect the fee?
    No, the bitcoin amount you're sending has no bearing on the fee. Fee (sats) = feerate (sat/vB) x vsize (vB), and vsize depends only on your transaction's inputs, outputs, and address type, never on the value they move. A transfer of 0.001 BTC and one of 10 BTC pay identical fees when they share the same size and feerate.
  • Why do different wallets show different fee estimates?
    Different wallets show different fee estimates because they poll different fee-estimation sources, or the same source at different moments, and mempool conditions shift by the minute. Some wallets also round to conservative tiers or add a safety margin to avoid an underpaid transaction. None of that changes the underlying formula. What differs is each wallet's guess at the feerate needed to land in your target confirmation window.
  • What's an optimal fee range?
    An optimal fee range is the lowest feerate that still clears within your target confirmation window, which changes with mempool congestion rather than sitting at a fixed number. Paying the fastest tier's rate guarantees next-block confirmation regardless of congestion. Paying near the slow tier's rate risks a multi-day wait if the backlog grows before your transaction gets picked up. Check the current tiers above rather than relying on a remembered number.
  • Can you speed up a transaction that's stuck in the mempool?
    Yes, two established methods exist for a stuck or underpaid transaction. Replace-By-Fee (RBF) rebroadcasts a new version of the same transaction — same inputs, higher feerate — if your wallet flagged it as replaceable when you sent it. Child-Pays-For-Parent (CPFP) is a new, high-fee transaction that spends an unconfirmed output, giving miners an incentive to confirm the stuck parent alongside it. Not every wallet supports both, so check what your wallet allows before you need it.