How to calculate the Net APY that is displayed for users on https://app.compound.finance/

net_apy.md

Net APY Calculation

1. Convert all supplied and borrowed asset amounts to a single asset (like USD or ETH).
2. Calculate the sum of (suppliedAmount * supplyApyAsDecimal - borrowedAmount * borrowApyAsDecimal) for all underlying assets.
3. If the calculated sum from the previous step is >0 then Net APY = 100 * (sum / totalSuppliedValue). If the calculation from the previous step is <0 then Net APY = 100 * (sum / totalBorrowedValue). If the calculation from the previous step is 0 then Net APY = 0.

Example

Net APY:

• -7.29%

Supplied Assets:

• 0.6 ETH ($260.20) @ 1.11% APY

Borrowed Assets:

• 75 BAT ($26.56) @ 5.57% APY
• 100.02 USDT ($100.02) @ 10.64 APY%

Calculation:

(260.20 * 0.0111 - 0 * 0) + (0 * 0 - 26.56 * 0.0557) + (0 * 0 - 100.02 * 0.1064) = -9.2333

100 * (-9.2333 / (26.56 + 100.02)) = -7.294438299889398

-7.29%

Hm, something is not adding up. I did an example calculation and got a very different value than shown on the website, perhaps it's because the website somehow includes COMP while you don't? Not sure how, though.

I get a very different value in my testing application