🕊️Kusama SRB

Learn how Kusama staking rewards are calculated. KSMSRB uses the Substrate era-based reward model with era validator rewards and total staked KSM.

KSMSRB is a benchmark representing the annualized staking rate for the KSM token.

KSMSRB is calculated and published by Staking Rewards via the Kusama Profile and Data API.

TL;DR: Kusama staking rewards use the Substrate era-based reward model: era validator rewards annualized over 365 days divided by total staked KSM tokens. Validator-level rates are adjusted by commission in the Nominated Proof of Stake system.

KSM Staking Rewards Rate: KSMSRB

KSMSRB = evr * t_y / st

Formula Key

Metric Name

Description

evr

Era Validator Reward

The total reward distributed to all validators for the previous era, sourced directly from on-chain storage.

Staked Tokens

The total staked KSM in the active era, sourced from on-chain era total stake.

$t_y$

Year Constant

1460 eras — used to annualize the per-era reward (6-hour eras).

KSMSRB is non-compounded, excluding returns from reinvestment of rewards.
The reward rate is derived from actual on-chain era rewards, not from an inflation model estimate.
Both claimed and unclaimed rewards are included.

Slashing

KSMSRB does not factor in the possibility of slashing occurrences.
Kusama implements Substrate's standard slashing mechanism. Validators can be slashed for equivocation or prolonged unresponsiveness.

KSM Validator Staking Rewards Rate: KSMSRB(v)

Staking Rewards calculates the KSMSRB for each validator based on their individual era points (performance) and commission rate.

KSMSRB(v) = (vep / tep * tvr) / t_m * t_y / vst

Formula key

Metric Name

Description

$vep$

Validator Era Points

Validator era points accumulated in the observation period.

tep

Total Era Points

Total era points for all validators in the observation period.

tvr

Total Validator Rewards

All rewards distributed to all validators in the observation period.

vst

Validator Staked Tokens

Validator staked tokens, self-staked and nominated.

$t_y$

Year Constant

365d

$t_m$

Month Constant

30d

Observation Period:

The KSMSRB is determined based on the latest completed era at the evaluation point.
This data is then annualized for a comprehensive year-long projection.

Calculation

The calculation happens every 6 hours and is immediately published via Data API.

Limitations

KSMSRB employs a 365-day convention for annualizing era reward data. This convention remains consistent and does not accommodate adjustments for leap years.

KSM Real Reward Rate: KSMSRB^R

The real reward rate calculates the reward rate adjusted for inflation in the network.

KSMSRB^R = 1+KSMSRB/(1+ir)-1

Formula key

Metric name

Description

Inflation Rate

Derived from on-chain era rewards: eraValidatorReward * 1460 / totalSupply.

Inflation Rate Behavior

Kusama's inflation is determined by the NPoS inflation curve, which dynamically adjusts based on the staking ratio. The network targets an ideal staking ratio, directing a larger share of inflation to stakers when participation is below target and more to the treasury when above. The inflation rate is derived from actual on-chain era rewards, reflecting the real-time state of the network.