# Fee rate: sats per vbyte

Fee rate is the fee divided by virtual size, in sats per vbyte (sat/vB). It is the number miners sort by. Learn how to calculate and choose one.

Canonical page: https://mybitcoinexplorer.com/learn/fee-rate-sat-per-vbyte
Topic: Transactions
Published: 2026-10-29
Updated: 2026-10-30


## The formula
~~~
fee rate (sat/vB) = fee (sats) ÷ virtual size (vB)
~~~

### Worked example: Working it out
A transaction is 141 vB and pays 1,410 sats. Its fee rate is 1,410 ÷ 141 = **10 sat/vB**. Another transaction of 282 vB paying 2,000 sats pays more in total but only **7.1 sat/vB**, so a miner prefers the first one.


## Why miners sort by rate
A block has room for a fixed amount of weight. To earn the most, miners fill it with the highest-paying transactions per unit of space, a bit like packing a suitcase with the most valuable items per centimetre.

> Diagram: Miners pick the highest fee rates from the mempool first — 

## Choosing a rate
- **Next block:** look at current estimates for 1 block.
- **Within an hour:** a 6-block target is usually much cheaper.
- **Whenever:** use a low rate and wait for a quiet period, but not below what nodes will relay (see [Relay policy and standardness](https://mybitcoinexplorer.com/learn/relay-policy-and-standardness)).

> Estimates come from what recently confirmed. They are predictions, not promises.


## Worked example: what will I pay?
A typical native SegWit payment with one input and two outputs is about 141 vB.

| Fee rate | Fee | In BTC |
|---|---|---|
| 1 sat/vB | 141 sats | 0.00000141 |
| 5 sat/vB | 705 sats | 0.00000705 |
| 20 sat/vB | 2,820 sats | 0.0000282 |

## Older units you may see
Some tools show **sat/byte** (the same as sat/vB for legacy transactions) or **BTC/kvB**, as Bitcoin Core's `estimatesmartfee` does. To convert BTC/kvB to sat/vB, multiply by 100,000.


## Key takeaways

- Fee rate = fee ÷ virtual size, measured in sat/vB.
- Miners prioritise by fee rate, not total fee.
- Pick a target based on how soon you need confirmation.

## Common questions

### What is a vbyte?

A virtual byte: transaction weight divided by four. It accounts for the SegWit discount.

### What fee rate should I use?

Check a current estimate. Fee rates change with demand, from 1 sat/vB on quiet days to much higher when blocks are full.

### What is a good fee rate right now?

It changes with demand. Check the MyBitcoinExplorer fee page for our node's current estimates.

### Is sat/vB the same as sat/byte?

For legacy transactions yes; for SegWit transactions vbytes account for the witness discount, so sat/vB is the correct measure.

## Related lessons

- [How Bitcoin transaction fees work](https://mybitcoinexplorer.com/learn/bitcoin-transaction-fees)
- [Transaction size, weight and vbytes](https://mybitcoinexplorer.com/learn/transaction-size-and-weight)
- [What is the Bitcoin mempool?](https://mybitcoinexplorer.com/learn/what-is-the-mempool)
- [Child pays for parent (CPFP)](https://mybitcoinexplorer.com/learn/child-pays-for-parent-cpfp)