Calculate amount of borrowable asset in Isolated/Cross margin trade with a predefined Risk Ratio

Hello Readers,
Need your help to derive a formula to calculate the borrowable asset with a Risk Ratio of 2 in ISOLATED/CROSS marginal trade. Let me explain, i want to short BTC/USDT (Isolated/Cross) in Binance. I need to find how much max BTC i can borrow by keeping the Risk Ratio 2.0.

Collateral asset (USDT) = CA
Available coin (BTC) = AV
Risk Ratio = RR
Interest on borrowable asset = I%

Borrowable asset BA = ?

*Feel free to add more parameters if required for calculation.

Also, it would be much appreciated if you can help me with the API endpoint that will give you ‘Available coin’.
Thanks in advance

Have a look at this thread for calculating liquidation price, which also includes the risk ratio.

Also, it would be much appreciated if you can help me with the API endpoint that will give you ‘Available coin’.

Assets
https://binance-docs.github.io/apidocs/spot/en/#all-coins-39-information-user_data

Symbols
https://binance-docs.github.io/apidocs/spot/en/#exchange-information

Hi Ale, Thanks for the response. I am aware of the links you shared. The first link is for calculating Margin Liq. Price. But my requirement is not that. To make the equation useful for me, i already need to calculate the Liq Price then only you could find the borrow able asset. I need to calculate the borrow able amount before placing the order. For my second query, I believe I’ve confused you.
The rectangle area i marked in attached screenshot is the one i am looking for.


Thank You

check the tickets

/sapi/v1/margin/account (HMAC SHA256)
/sapi/v1/margin/isolated/account (HMAC SHA256)
/sapi/v1/margin/maxBorrowable (HMAC SHA256)

The first two are used to obtain the free of an asset and with the last one you obtain the maximum amount to borrow

Hi Saratoga,
Unfortunately the solution provided is not working. The free asset you mentioned is same as the collateral i transferred and not the available asset that i could borrow with my collateral. I have prepared few samples that could be helpful to understand my problem statement. Also keep in mind that i haven’t borrowed any asset at this moment. I need to ;
1. first calculate the borrowable asset with the collateral in isolated/cross. (Yellow rectangle portion in the screenshot)
2. Secondly, if i get the available asset from above step, i could calculate the MAX borrowable asset with RiskRatio <=2.0.
Hope you understood my requirement now.

Thank You

For isolated margin use the following input

/sapi/v1/margin/isolated/account

there you divide the free of the quoteAsset between the indexPrice and multiply them by the MarginRatio and thus obtain the available from the base asset, as for the crossed margin I do not know of any entry that returns the same data as the entry of the isolated margin

As you can see in the following image you can consult the maximum to borrow from the base asset even if you do not have it funded, as you can see I do not have any BTC in the BTCUSDT pair, I only have USDT even so when making a consultation of the maximum to borrow I returns the amount of 0.05593948 BTC that I can borrow having 132.9539541 USDT and 0 BTC in the BTCUSDT pair

I’ve figured it out, the formula is;

Maximum amount of borrow = min (net assets in each isolated margin account(estimated leverage in the corresponding isolated margin account -1) - assets to be refunded)*

“estimated leverage in the corresponding isolated margin account” - This is actually creating all the confusion. For isolated margin, it is not the leverage that is shown in the platform (10x, 5x, or 3x). Its is actually the effective leverage based on the amount of user’s borrowed funds and it should be <= MAX leverage shown in the platform. Read more Tiered Leverage Function on Isolated Margin | Binance Support.
To find which tier user’s account belongs to can be obtained from the endpoint /sapi/v1/margin/isolatedMarginTier.
The ‘effectiveMultiple’ parameter will give you the estimated margin.