# Supply Rate

At any point in time one may query the contract to get the current supply rate per block. The supply rate is derived from the [borrow rate](https://docs.belugas.io/atokens/borrow-rate), [reserve factor](https://docs.belugas.io/atokens/reserve-factor) and the amount of [total borrows](https://docs.belugas.io/atokens/total-borrow).

**BErc20 / CEther**

```
function supplyRatePerBlock() returns (uint)
```

* `RETURN`: The current supply rate as an unsigned integer, scaled by 1e18.

**Solidity**

```
BErc20 bToken = BToken(0x3FDA...);
uint supplyRateMantissa = bToken.supplyRatePerBlock();
```

**Web3 1.0**

```javascript
const bToken = CEther.at(0x3FDB...);
const supplyRate = (await bToken.methods.supplyRatePerBlock().call()) / 1e18;
```