Polkadot Parameters
Many of these parameter values can be updated via on-chain governance. If you require absolute certainty of these parameter values, it is recommended you directly check the constants by looking at the chain state and/or storage.
Periods of common actions and attributes¶
NOTE: Polkadot generally runs at ¼th the speed of Kusama, except in the time slot duration itself.
- Slot: 6 seconds *(generally one block per slot, although see note below)
- Epoch: 4 hours (2_400 slots x 6 seconds)
- Session: 4 hours (Session and Epoch lengths are the same)
- Era: 24 hours (6 sessions per Era, 2_400 slots x 6 epochs x 6 seconds)
| Polkadot | Time | Slots* |
|---|---|---|
| Slot | 6 seconds | 1 |
| Epoch | 4 hours | 2_400 |
| Session | 4 hours | 2_400 |
| Era | 24 hours | 14_400 |
- Slot: 6 seconds *(generally one block per slot, although see note below)
- Epoch: 1 hour (600 slots x 6 seconds)
- Session: 1 hour (6 sessions per Era)
- Era: 6 hours (3600 slots x 6 seconds)
| Kusama | Time | Slots* |
|---|---|---|
| Slot | 6 seconds | 1 |
| Epoch | 1 hour | 600 |
| Session | 1 hour | 600 |
| Era | 6 hours | 3_600 |
*A maximum of one block per slot can be in a canonical chain. Occasionally, a slot will be without a block in the chain. Thus, the times given are estimates. See Consensus for more details.
Governance¶
| Parameter | Time | Slots | Description |
|---|---|---|---|
| Voting period | 28 days | 403_200 | How long the public can vote on a referendum. |
| Enactment period | 28 days | 403_200 | Time it takes for a successful referendum to be implemented on the network. |
| Parameter | Time | Slots | Description |
|---|---|---|---|
| Voting period | 7 days | 100_800 | How long the public can vote on a referendum. |
| Enactment period | 8 days | 115_200 | Time it takes for a successful referendum to be implemented on the network. |
Staking, Validating, and Nominating¶
The maximum number of validators that can be nominated by a nominator is can be see here.
| Parameter | Time | Slots | Description |
|---|---|---|---|
| Term duration | 1 Day | 14_400 | The time for which a validator is in the set after being elected. Note, this duration can be shortened in the case that a validator misbehaves. |
| Nomination period | 1 Day | 14_400 | How often a new validator set is elected according to Phragmén's method. |
| Bonding duration | 28 days | 403_200 | How long until your funds will be transferrable after unbonding. Note that the bonding duration is defined in eras, not directly by slots. |
| Slash defer duration | 28 days | 403_200 | Prevents overslashing and validators "escaping" and getting their nominators slashed with no repercussions to themselves. Note that the bonding duration is defined in eras, not directly by slots. |
| Parameter | Time | Slots | Description |
|---|---|---|---|
| Term duration | 6 hours | 3_600 | The time for which a validator is in the set after being elected. Note, this duration can be shortened in the case that a validator misbehaves. |
| Nomination period | 6 hours | 3_600 | How often a new validator set is elected according to Phragmén's method. |
| Bonding duration | 7 days | 604_800 | How long until your funds will be transferrable after unbonding. Note that the bonding duration is defined in eras, not directly by slots. |
| Slash defer duration | 7 days | 604_800 | Prevents overslashing and validators "escaping" and getting their nominators slashed with no repercussions to themselves. Note that the bonding duration is defined in eras, not directly by slots. |
Treasury¶
| Treasury | Time | Slots | Description |
|---|---|---|---|
| Periods between spends | 24 days | 345_600 | When the treasury can spend again after spending previously. |
Burn percentage is currently 1.00%.
| Treasury | Time | Slots | Description |
|---|---|---|---|
| Periods between spends | 6 days | 86_400 | When the treasury can spend again after spending previously. |
Burn percentage is currently 0.20%, though instead of being burned this amount is temporarily
redirected into the Society's treasury to
fund growth.
Precision¶
DOT have 10 decimals of precision. In other words, 10 ** 10 (10_000_000_000 or ten billion) Plancks make up a DOT.
The denomination of DOT was changed from 12 decimals of precision at block #1,248,328 in an event known as Denomination Day. See Redenomination for details.
KSM have 12 decimals of precision. In other words, 1e12 (1_000_000_000_000, or one trillion) Plancks make up a single KSM.