What is Sat/Byte
Satoshi per byte (sat/vB) measures your Bitcoin transaction fee rate. Miners select transactions with the highest sat/vB to fill blocks and maximize revenue.
- Fee Rate
- Bitcoin Basics
- vByte
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Master Bitcoin fee rates — from 1 sat/vB basics to mempool congestion strategies
Free guides, calculators, and live sat/vByte data for every Bitcoin user
21
million BTC transactions/yearUnderstand Bitcoin Fees: Satoshi Per Byte (Sat/vByte) Explained Clearly
Bitcoin transaction fees are determined by the amount of data (in bytes or virtual bytes) your transaction occupies in a block — not by the amount of BTC you send. A higher sat/vB rate signals miners to prioritize your transaction. Understanding this mechanism helps you save money and avoid stuck transactions.
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Satoshi per byte (sat/vB) is the standard unit for measuring Bitcoin transaction fees. One satoshi = 0.00000001 BTC. Miners prioritize transactions with higher sat/vB rates, making this metric essential for every Bitcoin user who wants fast, reliable confirmations.
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Min Confirmation
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II.
Block Size (MB)
0MB
III.
Sats Per Bitcoin
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Avg Block Time
0min
Bitcoin Fee Resources
01
02
Bitcoin Fee Calculator
Estimate the optimal sat/vByte for your transaction based on current mempool depth. Choose fast, medium, or economy confirmation tiers.
- Calculator
- Mempool
- Estimation
03
SegWit vs Legacy Fees
SegWit reduced effective transaction costs by up to 54% by introducing virtual bytes. Learn how P2WPKH and P2TR address types slash your sat/vB costs.
- SegWit
- Taproot
- vBytes
04
Mempool & Fee Market
The mempool is Bitcoin's fee auction. When blocks fill up, fee rates spike. Understand how to read mempool depth charts and time your transactions.
- Mempool
- Congestion
- Fee Market
05
How to Set Fees
Practical strategies for setting the right sat/vByte: wallet settings, RBF, CPFP, batching, and UTXO management to minimize costs.
- Wallets
- RBF
- CPFP
06
Fee Rate History
From near-zero in 2009 to 2,000+ sat/vB during the 2024 halving, explore how Bitcoin's fee market has evolved and what drives spikes.
- History
- Data
- Trends
How Fee
Rates Work
Every Bitcoin transaction competes for limited block space. The sat/vByte rate you set determines how quickly miners include your transaction.
01 Broadcast
Transaction Enters the Mempool
When you broadcast a Bitcoin transaction, it enters the mempool — a pool of unconfirmed transactions waiting for inclusion in a block.
02 Fee Auction
Miners Sort by Sat/vByte
Miners sort pending transactions by fee rate (sat/vB). Higher sat/vByte means higher priority. When the mempool is congested, lower-fee transactions wait longer.
03 Confirmation
Block Confirmation & Security
Once a miner includes your transaction in a block and that block is added to the blockchain, your transaction receives its first confirmation. Each subsequent block adds another confirmation.
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Bitcoin Fee FAQ
Satoshi per byte (sat/vB) is the unit for measuring Bitcoin transaction fee rates. It represents the number of satoshis (0.00000001 BTC each) you are willing to pay per virtual byte of transaction data. Miners prioritize transactions with higher sat/vB rates.
During normal network conditions, 5–15 sat/vB is usually sufficient for confirmation within 1–3 blocks (10–30 minutes). During high congestion, rates may need to be 50–200+ sat/vB. Always check a live mempool explorer before sending time-sensitive transactions.
A virtual byte (vB) is a unit introduced by SegWit. Non-witness transaction data has a weight of 4, while witness (signature) data has a weight of 1. Total weight is divided by 4 to get vBytes. This means SegWit transactions are smaller in vB, reducing their effective fee cost.
Fee spikes occur when demand for block space exceeds supply. Causes include Bitcoin price rallies attracting new users, inscription and Ordinals activity, and exchange withdrawal backlogs. Since blocks are capped at ~1 MB, users bid up fees to compete for limited space.
Replace-By-Fee (RBF) lets you replace an unconfirmed transaction with a new version that pays a higher fee. This is useful if your transaction gets stuck due to a fee that was too low. Most modern Bitcoin wallets support RBF by default. An alternative is CPFP (Child-Pays-For-Parent).