What is a block halving?
A block halving is a process of reducing the rate at which new cryptocurrency units are generated. Specifically, it refers to the periodical halving events that decrease the block rewards provided to miners.
Why are halvings significant?
Halvings are at the core of the cryptocurrency economic models because they ensure coins will be issued at a steady pace, following a predictable decaying rate. Such a controlled rate of monetary inflation is one of the main differences between cryptocurrencies and traditional fiat currencies, which essentially have an infinite supply.
The chart below depicts the inflation rate curve of CKB as halvings occur. It's evident that prior to the first halving in November 2023, CKB had an inflation rate of 7.92%. After the first halving, the inflation rate will decrease to 3.77%, and with each subsequent halving, it will approach 0%.
How does the CKB Halving work?
The base issuance of CKB are rewarded to miners for securing the network, and the reward halves approximately every 4 years until all the base issuance tokens (33.6 billion) are mined out.
In order to make the halving plan work as expected, a concept of time called epoch was introduced.
An epoch is a period of time for a set of blocks.
In Nervos, the PoW difficulty changes on a new epoch. All the blocks in the same epoch share the same difficulty target. The difficulty adjustment algorithm aims to stabilize the orphan block rate at 2.5% and the epoch duration at 4 hours.
Epochs per halving is 4 * 365 * (24 / 4) = 8760, and the Nth halving of CKB firstly occurs on epoch: the_Nth_halving_epoch = 8760 * N .
So, The CKB halving event occurs on the specified epoch, e.g. 8760, 17520:
When will CKB be halved?
The following table details the schedule for several upcoming CKB halvings and their corresponding base issuance rewards:
| Event | Date | Epoch number | Epoch reward | Block reward(Calculated based on 1800 blocks per epoch) | Daily reward | Total new CKB between events |
|---|---|---|---|---|---|---|
Nervos launches | 16 Nov 2019 | 0 (genesis epoch) | 1,917,808 CKB | 1,065 CKB | 11,506,849 CKB | 16,800,000,000 CKB |
First halving | 19 Nov 2023 | 8,760 | 958,904 CKB | 533 CKB | 5,753,424 CKB | 8,400,000,000 CKB |
| Second halving | Expected November 2027 | 17,520 | 479,452 CKB | 266 CKB | 2,876,712 CKB | 4,200,000,000 CKB |
| 3rd halving | Expected November 2031 | 26,280 | 239,726 CKB | 133 CKB | 1,438,356 CKB | 2,100,000,000 CKB |
| 4th halving | Expected November 2035 | 35,040 | 119,863 CKB | 67 CKB | 719,178 CKB | 1,050,000,000 CKB |
| 5th having | Expected November 2039 | 43,800 | 59,932 CKB | 33.5 CKB | 359,589 CKB | 525,000,000 CKB |
| 6th having | Expected November 2043 | 52,560 | 29,966 CKB | 16.75 CKB | 179,794.5 CKB | 262,500,000 CKB |
| 7th having | Expected November 2047 | 61,320 | 14,983 CKB | 8.375 CKB | 89,897.25 CKB | 131,250,000 CKB |
| 8th having | Expected November 2051 | 70,080 | 7,491 CKB | 4.1875 CKB | 44,948.625 CKB | 65,625,000 CKB |
| 9th having | Expected November 2055 | 78,840 | 3,746 CKB | 2.09375 CKB | 22,474.3125 CKB | 32,812,500 CKB |
| 10th having | Expected November 2059 | 87,600 | 1,873 CKB | 1.046875 CKB | 11,237.15625 CKB | 16,406,250 CKB |
The following chart shows the daily mining rewards after each halving:
The following chart shows the mining rewards for each epoch before and after the halving:
⚠️ Note that CKB block rewards include Base (issuance) reward, Secondary (issuance) reward, Commit reward, and Proposal reward:
However, when we are discussing CKB halving, it only relates to Base issuance rewards. Therefore, the block rewards listed in the table only include the portion of rewards from base issuance to help with understanding.
How is our timer calculated?
You may notice our countdown has a different estimation than other CKB halving countdowns and ask "Why?"
We believe this makes our countdown more accurate because instead of using the commonly quoted average epoch time (4 hours), we are using live blockchain statistics and obtaining an estimation of the current epoch time, then conducting our calculation based on that. Our timer may fluctuate, however, we believe it is the most accurate CKB halvings clock.
The CKB halvings timer on ckbdapps.com is calculated using the following formula:
(Halving epoch index - Next epoch index) * Average time between epochs - estimated time until the next epoch.