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Data / Block size and transactions per block / 2021
The average size of a bitcoin block in megabytes, and how many transactions each block carried.
Average block size opened 2021 at 1.35 MB (January 1, 2021) and closed at 1.39 MB (December 31, 2021), up 3.1%. The high was 1.51 MB on October 21, 2021 and the low 0.76 MB on August 14, 2021.
| Month | Month end |
|---|---|
| January 2021 | 1.31 MB |
| February 2021 | 1.36 MB |
| March 2021 | 1.35 MB |
| April 2021 | 1.39 MB |
| May 2021 | 1.44 MB |
| June 2021 | 1.36 MB |
| July 2021 | 0.82 MB |
| August 2021 | 1.14 MB |
| September 2021 | 1.25 MB |
| October 2021 | 1.12 MB |
| November 2021 | 1.24 MB |
| December 2021 | 1.39 MB |
Blocks have been effectively full since 2016. Since SegWit in 2017 a block can weigh up to 4 MB, so an average above 1 MB means users are paying for the extra space. Fewer transactions per block at the same size means bigger transactions, which is what inscriptions and batching look like.
Other years: 2026 · 2025 · 2024 · 2023 · 2022 · 2020 · 2019 · 2018 · 2017 · 2016 · 2015 · 2014 · 2013
Also in 2021: Bitcoin price · Distance from the all-time high · 200-day and 200-week averages · Network hashrate · Mining difficulty · Difficulty adjustments · Fees paid to miners · Transactions per day · Hashprice · Miner revenue · Bitmain releases and the bitcoin price · Break-even electricity price