Parameters
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. See Kusama Parameters for more details on how Polkadot's parameters differ from Kusama's.
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)
Slot
6 seconds
1
Epoch
4 hours
2_400
Session
4 hours
2_400
Era
24 hours
14_400
*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.
Accounts, Identity and Crowdloans
The Existential Deposit is 1.000 DOT
The deposit required to set an Identity is 20.258 DOT
The minimum contribution required to participate in a crowdloan is 5.000 DOT
Governance
Voting period
28 days
403_200
How long the public can vote on a referendum.
Launch period
28 days
403_200
How long the public can select which proposal to hold a referendum on, i.e., every week, the highest-weighted proposal will be selected to have a referendum.
Enactment period
28 days
403_200
Time it takes for a successful referendum to be implemented on the network.
Term duration
7 days
100_800
The length of a council member's term until the next election round.
Voting period
7 days
100_800
The council's voting period for motions.
The Polkadot Council consists of up to 13 members and up to 20 runners up.
Cool-off period
7 days
100_800
The time a veto from the technical committee lasts before the proposal can be submitted again.
Emergency voting period
3 hours
1_800
The voting period after the technical committee expedites voting.
Staking, Validating, and Nominating
Maximum number of Validators that can be nominated by a nominator - 16
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.
Parachains
Auction duration
7 days
100_800
The total duration of the slot auction, subject to the candle auction mechanism.
Opening period
2 days
28_800
The opening period of the slot auction.
Ending period
5 days
72_000
The ending period of the slot auction.
Lease period
12 weeks
1_209_600
The length of one lease period in a parachain slot.
Total slot duration
2 years
10_512_000
The maximum duration a parachain can lease by winning a slot auction (8 lease periods).
Treasury
Periods between spends
24 days
345_600
When the treasury can spend again after spending previously.
Burn percentage is currently 1.00%.
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.