Overview
Understanding why Bitcoin transactions may take time to be confirmed is essential, especially when dealing with critical operations like loans or payments.
Two primary factors influence how long a Bitcoin transaction takes: blocktime and transaction fees. This article breaks down these factors and their role in transaction delays.
Blocktime
What is Blocktime?
Block time refers to the approximate time it takes for a blockchain-based system to produce a new block.
Block time refers to the approximate time it takes for a blockchain-based system to produce a new block, dictating the speed of transaction confirmation, which is measured in transactions per second (TPS).
Bitcoin has an average blocktime of approximately 10 minutes.
Why Blocktime Matters
Transactions are included in blocks. A transaction can only be confirmed when a miner adds a new block to the blockchain.
Since new blocks are added at intervals of roughly 10 minutes, your transaction will only be confirmed when it's included in one of these blocks.
Transactions that miss the current block must wait for the next block to be added, causing delays.
Effects of Blocktime on Transactions
In periods of network congestion (many transactions waiting to be confirmed), transactions may take multiple blocks (multiple 10-minute intervals) to be confirmed.
Even during periods of low congestion, there is a minimum waiting time equal to one blocktime (around 10 minutes) for the first confirmation.
Transaction Fees
Transaction Fees on Bitcoin are measured in sats/vB. The transaction fees are calculated by multiplying the transaction size in virtual Bytes (vB) by the current fee rate (sats/vB). If a transaction has 1,000vB and the current rate is 10sats/vB then the transaction cost equals 10,000sats (satoshis) which is equivalent to 0.00010000 BTC.
How Transaction Fees Work
Bitcoin uses a fee-based incentive system to prioritize transactions.
Users include fees in their transactions to incentivize miners to add their transaction to the next block.
Low vs. High Fees
High Fees: Transactions with higher fees are more likely to be picked up by miners quickly. These transactions are included in the next available block, reducing wait time.
Low Fees: Transactions with lower fees are less prioritized by miners. If the network is congested, transactions with low fees can be left unconfirmed for extended periods until miners have space in the block to include them.
Dynamic Fee Markets
During times of high demand (network congestion), users compete by offering higher fees to prioritize their transactions.
Fees fluctuate based on the number of unconfirmed transactions waiting in the mempool (the queue of transactions waiting to be added to blocks).
If the mempool is full, only transactions with higher fees will be processed quickly, while low-fee transactions might remain in the mempool for hours or even days.
Interplay Between Blocktime and Fees
Combined Impact
Blocktime defines the intervals at which new transactions can be confirmed, while transaction fees determine how likely your transaction is to be included in the next block.
Even if blocktimes remain stable (around 10 minutes), transactions with low fees can experience significant delays because they may be skipped in favor of higher-fee transactions.
Best Practices to Avoid Delays
Set Appropriate Fees: Always check current network conditions and set fees that will prioritize your transaction according to how quickly you need it confirmed.
Monitor Mempool Activity: Check the size of the mempool to gauge network congestion. A full mempool means you may need to offer higher fees to get timely confirmation.
Use Fee Adjustments: Consider using CPFP if your transaction is delayed. CPFP allows you to increase the fee of an unconfirmed transaction to push it through faster.
Conclusion
The time it takes for a transaction to be confirmed on the Bitcoin network is primarily influenced by blocktime and transaction fees. Understanding how these factors work together can help users avoid delays and ensure their transactions are processed within the desired timeframe. By offering appropriate fees and understanding the nature of Bitcoin's block intervals, users can optimize their transaction speeds and reduce waiting time.