Mempool Size
- 1M1M
- 3M3M
- 6M6M
- 1Y1Y
- ALLALL
- LinearLinear
- LogLog
About this metric
What it measures
Mempool Size adds the virtual sizes of unconfirmed transactions held in the observed queue, in virtual bytes (vB). Virtual size reflects transaction weight, so the measure describes pending block-space demand rather than raw file size or memory consumption.
How to read it
Growth means the queue represents more virtual block space; contraction means less remains pending. The series reached 137.52 million vB on January 27, 2024, while its full-history median is about 5.67 million vB. These are accumulated queue sizes, not bytes added each day.
A larger queue need not raise near-term fees if most of it offers very low rates. Node admission and eviction policies shape the backlog, and the daily sampling misses changes within the day. Use the fee-tier size profile to see where the virtual bytes sit in the bidding range.
- Frequency
- Daily (UTC 00:00)
- Asset
- BTC
- Category
- Mempool
- Type
- Single value
- Unit
- vB
- Data since
- 2021-10-15
- Latest data
- 2026-10-27
- Data points
- 1,839
FAQ
Is this chart measured in bytes or virtual bytes?
The configured unit is vB, meaning virtual bytes. This differs from serialized transaction bytes and from the RAM a node needs to store the mempool.
How does mempool size differ from mempool transaction count?
Size sums virtual bytes; count treats each transaction as one entry. A large consolidation can add much more size than a simple transfer while adding the same one transaction to the count.
Can a large mempool coexist with low fees?
Yes. A large backlog of low-rate transactions can wait while higher-rate arrivals clear. Total size does not show how much competition sits above a particular fee rate.
