# 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](https://polkadot.js.org/apps/#/chainstate/constants) and/or [storage](https://polkadot.js.org/apps/#/chainstate).
#### Periods of common actions and attributes[](https://wiki.polkadot.network/docs/maintain-polkadot-parameters#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*](https://guide.kusama.network/docs/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)
| Polkadot | Time | Slots\* |
| -------- | --------- | ------- |
| 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*](https://wiki.polkadot.network/docs/learn-consensus) *for more details.*
#### Accounts, Identity and Crowdloans[](https://wiki.polkadot.network/docs/maintain-polkadot-parameters#accounts-identity-and-crowdloans)
* The [Existential Deposit](https://wiki.polkadot.network/docs/learn-accounts#existential-deposit-and-reaping) 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[](https://wiki.polkadot.network/docs/maintain-polkadot-parameters#governance)
| Democracy | Time | Slots | Description |
| ---------------- | ------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| 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. |
| Council | Time | Slots | Description |
| ------------- | ------ | -------- | -------------------------------------------------------------------- |
| 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.
| Technical committee | Time | Slots | Description |
| ----------------------- | ------- | -------- | ---------------------------------------------------------------------------------------------- |
| 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[](https://wiki.polkadot.network/docs/maintain-polkadot-parameters#staking-validating-and-nominating)
Maximum number of Validators that can be nominated by a nominator - 16
| Polkadot | 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. |
#### Parachains[](https://wiki.polkadot.network/docs/maintain-polkadot-parameters#parachains)
| Crowdloans and Auctions | Time | Slots | Description |
| ----------------------- | ------ | -------- | -------------------------------------------------------------------------------- |
| 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. |
| Parachain Slot | Time | Slots | Description |
| ------------------- | -------- | ------------ | --------------------------------------------------------------------------------------- |
| 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[](https://wiki.polkadot.network/docs/maintain-polkadot-parameters#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%`.
#### Precision[](https://wiki.polkadot.network/docs/maintain-polkadot-parameters#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](https://wiki.polkadot.network/docs/redenomination) for details.