ChainTools

Bitcoin Fee Calculator

Fee rate times transaction size — what you'll actually pay to get a transaction confirmed.

Fee rate (sat/vByte)

Transaction size (vBytes)

Fee (sats)

4,500

A typical simple transaction is around 140-250 vBytes — check a mempool explorer for current recommended fee rates.

Fee (BTC): 0

What you entered

Fee rate (sat/vByte): 20Transaction size (vBytes): 225

1
Fee in satoshis = rate × transaction size
20 sat/vByte × 225 vBytes= 4500 sats
2
Convert to BTC
4500 ÷ 100,000,000= 0.00004500 BTC

Result

Fee (sats): 4,500

A 225 vByte transaction at 20 sat/vByte costs 4500 satoshis (0.000045 BTC).

Bitcoin transaction fee by fee rate and size

Fees are priced per virtual byte, not per amount sent. A simple one-input, two-output transaction is about 140 vBytes; more inputs make it larger and more expensive.

Fee rate	Transaction size	Fee (sats)	Fee (BTC)
1 sat/vB	140 vB	140	0.00000140
5 sat/vB	140 vB	700	0.00000700
20 sat/vB	140 vB	2,800	0.00002800
50 sat/vB	140 vB	7,000	0.00007000
100 sat/vB	140 vB	14,000	0.00014000
20 sat/vB	250 vB	5,000	0.00005000
20 sat/vB	400 vB	8,000	0.00008000

Sending 0.001 BTC and 10 BTC costs exactly the same fee if the transactions are the same size. Consolidating many small inputs is what makes a transaction expensive.

Fee rates change with network demand

Fee rates (sat/vByte) fluctuate based on how congested the Bitcoin network is at any given moment — check a current mempool/fee estimator rather than assuming a fixed rate, especially during high-demand periods.

Transaction size depends on inputs and outputs

A transaction with more inputs (combining multiple past receipts) or more outputs (paying multiple recipients) is larger in vBytes and costs more in fees — a simple one-input, two-output transaction is on the smaller end.

Frequently asked questions

My wallet says 20 sat/vByte and my transaction is 250 vBytes — what's the fee?

5,000 satoshis, which is 0.00005 BTC. At a $60,000 BTC price, that's about $3. Fee rates fluctuate with network demand — check a mempool explorer for current rates before sending.

Why is my transaction fee so high even though I'm sending a small amount?

Bitcoin fees depend on transaction size in vBytes, not the amount being sent. A transaction consolidating many small inputs is physically larger than one spending a single large input, so it costs more in fees regardless of the value transferred.

How do I reduce my Bitcoin transaction fee?

Wait for lower network congestion (weekends are often cheaper), consolidate small UTXOs during low-fee periods, use SegWit addresses (smaller vByte size), or batch multiple payments into a single transaction.

How is this different from the Ethereum gas calculator?

Bitcoin fees are based on transaction size in vBytes multiplied by a fee rate in sat/vByte. Ethereum fees are based on computational gas used multiplied by a gas price in Gwei. Different networks, different fee models.