About the Bitcoin Transaction Fee Calculator
This Bitcoin transaction fee calculator estimates what a transaction will cost before you send it. Bitcoin fees are not a percentage of the amount sent — miners charge by block space, priced in satoshis per virtual byte (sat/vB). So the fee depends on how big the transaction is, which depends on how many inputs (coins being spent) and outputs (recipients plus change) it has and what address type you use.
Pick your wallet’s address type, enter the number of inputs and outputs and the fee rate your wallet or a mempool explorer suggests, and the calculator returns the virtual size, the fee in sats and BTC, and its value in dollars. It is useful for comparing address types, deciding whether to consolidate many small UTXOs while fees are low, and sanity-checking a wallet’s fee estimate.
Sizes are standard estimates for single-signature spends, assuming every input and output uses the selected type. Multisig, inscriptions and unusual scripts are larger. The fee rate itself changes minute to minute with mempool demand, so check a live estimate right before you broadcast.
With the default inputs, the transaction fee is 1,410 sats. Change any value above to recalculate instantly.
How to use the bitcoin transaction fee calculator
- 1Choose the address type your wallet spends from (bc1q = native SegWit, bc1p = Taproot).
- 2Enter how many coins (UTXOs) the transaction spends and how many outputs it creates.
- 3Enter a fee rate from your wallet or a mempool explorer.
- 4Add the BTC price and the amount you are sending to see the fee in dollars and as a percentage.
- 5Use the table to compare a fast fee rate with a cheaper, slower one.
Formula and method
Transaction size is measured in virtual bytes (vB), where one vB equals four weight units. SegWit witness data is discounted, which is why native SegWit and Taproot inputs are much smaller than legacy ones. The estimate uses a fixed overhead (10 vB legacy, 10.5 vB SegWit) plus per-input sizes of 148 / 91 / 68 / 57.5 vB and per-output sizes of 34 / 32 / 31 / 43 vB for legacy, nested SegWit, native SegWit and Taproot respectively.
The size is rounded up to a whole vB and multiplied by the fee rate in sat/vB to get the fee in satoshis. Dividing by 100,000,000 converts sats to BTC, and multiplying by the BTC price gives the dollar cost. The amount you send does not change the fee.
- vsize
- Virtual size of the transaction in vbytes
- fee rate
- Price of block space in satoshis per vbyte
- 1 BTC
- 100,000,000 satoshis
Worked examples
Simple native SegWit payment at 10 sat/vB
One native SegWit input and two outputs come to 10.5 + 68 + 2 × 31 = 140.5 vB, rounded up to 141 vB. At 10 sat/vB the fee is 1,410 sats, or $1.41 with BTC at $100,000 — about 0.028% of a 0.05 BTC payment.
Legacy wallet spending 3 inputs at 20 sat/vB
Legacy inputs are 148 vB each, so 10 + 3 × 148 + 2 × 34 = 522 vB. At 20 sat/vB that costs 10,440 sats, or $10.44 — several times what the same payment would cost from a SegWit wallet.
Taproot consolidation, 2 inputs to 1 output at 5 sat/vB
Two Taproot inputs and one output: 10.5 + 2 × 57.5 + 43 = 168.5, rounded to 169 vB. At a low 5 sat/vB the consolidation costs 845 sats, about 85 cents.
Frequently asked questions
How are Bitcoin transaction fees calculated?+
The fee equals the transaction’s virtual size in vbytes multiplied by the fee rate in satoshis per vbyte. Size depends on the number of inputs and outputs and the address type, not on how much BTC you send.
What is a good sat/vB fee rate?+
It depends on mempool congestion. When blocks are not full, 1–5 sat/vB often confirms within hours; during busy periods next-block fees can exceed 50 sat/vB. Check a live mempool explorer or your wallet’s estimate right before sending.
Why do I pay a higher fee than someone sending more BTC?+
Because fees are charged on data size. A wallet spending many small UTXOs produces a large transaction even for a small amount, while a single large UTXO can move any amount in a small transaction.
Do SegWit and Taproot addresses really save fees?+
Yes. Witness data counts at one quarter weight, so a native SegWit input is about 68 vB versus 148 vB for legacy, and a Taproot key-path input is about 57.5 vB. Spending from these address types can cut fees by 40% or more.
What happens if my fee is too low?+
The transaction waits in the mempool until demand falls or it is dropped. Many wallets let you bump the fee with Replace-By-Fee (RBF) or speed it up with Child-Pays-For-Parent (CPFP).
Results are estimates for educational purposes and are not financial advice. Rates, fees and terms vary — confirm with your lender or a licensed advisor before making decisions.