# Fee rate

What a transaction pays per vbyte, why a witness byte costs a quarter of a base byte, and how BTI divides fees among the tokens a transaction was bought for.

URL: https://blockspace.wiki/concepts/fee-rate/

A transaction's [fee rate](https://blockspace.wiki/glossary/fee-rate/) is what it pays per virtual byte, written in sats per vbyte (sat/vB). Fee markets price [vbytes](https://blockspace.wiki/glossary/vbytes/), not raw bytes. This page covers what a rate means for different kinds of bytes, the figures Blockspace Holdings' documents record, and how [BTI](https://blockspace.wiki/glossary/bti/) carries fees in its books.

## What a rate buys

block.space's data-types reference states the rule: at a fee rate of f sat/vB, a [witness](https://blockspace.wiki/glossary/witness/) byte costs f/4 sats and a non-witness byte costs f sats. That follows from weight: a witness byte is 1 [weight unit](https://blockspace.wiki/glossary/weight-unit/) and a non-witness byte is 4, and a vbyte is a quarter of the weight. See [weight units and vbytes](/concepts/weight-units-and-vbytes/) and [the witness discount](/concepts/witness-discount/).

Blockspace Value Theory's appendix of formulas writes the cost of a mint the same way:

```
Mint cost        = fee_rate(sat/vB) × size(vB) × BTC_price
Mint cost per KB = (sat/vB) × (vB per KB) × ($/sat)
```

## Fee rates in the documents

BVT records the fee environment of early to mid 2026 as "sustained periods at 0.13–0.14 sat/vB, with AntPool accepting sub-1 sat/vB inscriptions", and calls it historically anomalous. Its worked example (§3.6) at 0.14 sat/vB:

```
Fee rate:        0.14 sat/vB
Block capacity:  1,000,000 vB
Witness ratio:   ~4 bytes per vB
Bytes per block: ~4,000,000 = 4,000 KB
Cost per block:  140,000 sats
At $100,000/BTC: $140 per 4 MB  =  $0.035 per KB
```

*BVT is a living document and an untested thesis.* It draws an accumulation objective from this example, "maximize kilobytes consumed per satoshi spent", which in practice means Taproot witness data at the lowest sustainable fee rate.

Rates below 1 sat/vB matter to [Blockspace Holdings' own Bitcoin node](https://blockspace.wiki/glossary/blockspace-holdings-node-and-indexers/), which relays them. See [relay policy](/concepts/relay-policy/).

## Two real transactions

From the BTI case studies (2026-08-10):

- **The first BRC-20 mint** (block 779,833): 155 vB, fee 4,650 sats.
- **A 3.9 MB jpeg inscription** (block 960,962): 977,936 vB, fee 1,476,683 sats. Its commit transaction, mined 56,161 blocks earlier, paid 406 sats more.

## How the books carry fees

BTI's ledger keeps every transaction's fee beside its sizes. The design document notes that fees need the outputs being spent and sizes do not, so the two may advance at different speeds, but a block is not observed until both exist. In the books, fees follow bytes. Ruleset v1's formula:

```
fee_i = poolFee · A_i / pool
```

A token's share of a transaction's fee is its share of the pool's bytes under [Book A](https://blockspace.wiki/glossary/book-a/), and an enabler's fee rides along with its bytes. In case 7, the jpeg's sat carries both fees, 1,477,089 sats, "the sat bought both", in the case study's words. In case 10, the first BRC-20 mint, the 4,650-sat fee splits between the sat and the tick by their Book A shares: about 3,913.98 sats and 736.02 sats.

## Live figures

Over the whole chain the census has counted 30,078,484,994,465 sats in fees, over 567.72 GB of vbytes (as of block 972,318, 2026-10-20 12:15:32 UTC).

The fees the books attribute to the four largest families by Book A (as of block 972,299, 2026-10-20 09:30:48 UTC):

| family (key) | fees attributed (sats) | Book A |
|---|---|---|
| Ordinal Sats (`sat`) | 604,023,782,900 | 56.13 GB |
| Runes (`rune`) | 248,847,428,574 | 33.05 GB |
| BRC-20 (`brc20`) | 331,317,657,239 | 17.49 GB |
| Alkanes (`alkane`) | 6,120,479,708 | 11.95 GB |

Sources:

- block.space docs: data types · https://block.space/docs/datatypes
- Blockspace Value Theory · https://block.space/docs/bvt
- Blockspace Holdings records
- block.space docs: BTI · https://block.space/docs/bti
- block.space meter and summary APIs · https://block.space/api/summary
- block.space protocols API · https://block.space/api/protocols

Live figures: census as of block 972,318, 2026-10-20 12:15:32 UTC; protocols as of block 972,299, 2026-10-20 09:30:48 UTC

Updated: 2026-10-20