Bitcoin Mempool & Transaction Fee (sat/vB) Calculator

Bitcoin Mempool & UTXO Fee Engine

Sick of Overpaying Bitcoin Network Transaction Fees?

Calculate exact Bitcoin transaction costs in Satoshis, Satoshis per virtual byte (sat/vB), Bitcoin (BTC), and USD currency based on transaction weight and mempool congestion.

⚠️ sat/vB Fee Model. Bitcoin fees scale linearly with virtual size (vBytes) based on input/output configurations rather than transfer amounts.

Wallet & Address Type Native SegWit (Bech32 - 1 Input / 2 Outputs) Nested SegWit (P2SH - 1 Input / 2 Outputs) Legacy (P2PKH - 1 Input / 2 Outputs) Custom Virtual Size (vBytes)

Virtual Size (vBytes)

Fee Rate (sat/vB)

Bitcoin Price ($ USD)

Total Fee (Satoshis)

3,500 sats

Total Fee (USD)

$3.33

Total Fee (BTC)

0.00003500 BTC

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Decoding Bitcoin Mempool Fees, Sat/vB Metrics & UTXO Economics

Unlike account-based networks, Bitcoin uses the UTXO (Unspent Transaction Output) model. Every transaction consumes previous outputs and creates new ones. Transaction fees are not calculated as a percentage of the amount transferred; instead, they are measured in satoshis per virtual byte (sat/vB) multiplied by the physical data weight of your transaction.

The Bitcoin Mempool & Transaction Fee Calculator lets users simulate transaction costs across different address standards (Native SegWit, Nested SegWit, and Legacy) based on live sat/vB congestion parameters.

Governing Mathematical Formulas

This client-side Bitcoin fee engine computes transaction expenses using standard mempool equations:

• 1 Bitcoin (BTC): Equivalency of 100,000,000 Satoshis (sats).
• Total Fee (Satoshis): Virtual Size (vBytes) × Fee Rate (sat/vB)
• Total Fee (BTC): Total Satoshis / 100,000,000
• Total Fee (USD): Total Fee (BTC) × Current Bitcoin Price ($)

Worked Calculation Examples

Consider executing a Native SegWit Transaction with a standard size of 140 vBytes when the network fee rate is 25 sat/vB and Bitcoin Price is $95,000.00:

• Total Fee in Satoshis: $140 \text{ vB} \times 25 \text{ sat/vB} = \mathbf{3,500 \text{ sats}}$.
• Total Fee in BTC: $3,500 / 100,000,000 = \mathbf{0.00003500 \text{ BTC}}$.
• Total Cost in Fiat USD: $0.00003500 \text{ BTC} \times \$95,000.00 = \mathbf{\$3.33}$.

Frequently Asked Questions

1. What is sat/vB in Bitcoin transactions?

sat/vB stands for satoshis per virtual byte. It represents the rate you pay miners to include your transaction data into a block. Higher sat/vB rates result in faster confirmation times during network congestion.

2. Why do address types (Native SegWit vs Legacy) affect fees?

Native SegWit (Bech32) addresses separate witness script data, offering greater data discounts which reduce virtual byte size, resulting in lower transaction fees compared to older Legacy formats.

3. What is a UTXO dust threshold?

A UTXO becomes "dust" when its fiat or satoshi value is smaller than the network fee required to spend it, rendering those funds economically unspendable.

4. Are my Bitcoin fee calculations private?

Yes. All calculations execute locally inside your browser using JavaScript logic. No wallet keys or transaction amounts are transmitted to external servers.

Last updated: October 2026