Bitcoin Fee Estimator & Educator
Learn how Bitcoin fees work and estimate transaction costs in real-time
Estimated Fee
Confirmation Time
Effective Rate
Transaction Size
Mempool Visualization
Or calculate based on inputs/outputs below
Current market range: 5-150 sat/vB
For USD fee calculation
More inputs = larger transaction = higher fee
Recipient + change (usually 2 outputs)
Target confirmation time (10-1440 min)
Current mempool size affects confirmation time
Fee Calculation Formula
Fee = Size × Rate
Example Calculation
Frequently Asked Questions
Bitcoin fees are calculated based on transaction size (in bytes) multiplied by the fee rate (satoshis per virtual byte). Formula: Fee = Transaction Size (vBytes) × Fee Rate (sat/vByte). The total is paid in satoshis (1 BTC = 100,000,000 sats).
sats/vByte (virtual bytes) accounts for SegWit discount. SegWit transactions use ~40% less block space than legacy transactions. sats/byte refers to actual bytes, while sats/vByte is the effective rate after SegWit discount.
Fees are determined by supply and demand. When more people want their transactions confirmed quickly, they bid higher fees. Factors include network congestion, block space competition, mempool size, and time-sensitive transactions.
Mempool is the waiting room for unconfirmed transactions. When it's full, transactions compete for limited block space by offering higher fees. A crowded mempool leads to higher fees, while an empty mempool means lower fees.
Check current mempool status, consider transaction urgency, use fee estimation tools, consider batching multiple payments, and use SegWit addresses for fee discounts. For non-urgent transactions, lower fees can save money.
Low-fee transactions may take hours or days to confirm, or might get stuck. Most wallets have replace-by-fee (RBF) to increase fees later. After 2 weeks, unconfirmed transactions are usually dropped from mempools.