Margin calculation

Hello everyone, please, I need your help.
I need you to help me understand how to calculate the margin needed for a transaction based on the total amount in the account, the risk per transaction and the broker's leverage.
For example, I have a demo account where I have about $ 250, the risk per transaction I use is 2%, and the broker offers me a 1:30 lever, on Dax. If I open a transaction under these conditions, I use approximately 0.31 lots for an order.
How can I find out the margin needed for a transaction?
Thank you for your patience.

The margin for currency pairs is calculated in the base currency as follows:
Margin = V (lots) × Contract / Leverage, where: Margin — deposit required to open the position. ...

Accordingly; 0.1 lots = 0.1× 100,000 = 10,000 units of the base currency, then divide by your leverage.
Dax is quoted in units / USD

Then, You need to be sure what's the contract size of Dax that your broker defined. I never traded Dax and any other CFDs other than FX currencies, I'm not familiar with different contract sizes. But I'll calculate according to my broker's Dax contract size (maybe it's same in everywhere, I'm not familiar, check yourself). 1 lot equal to 1 unit according to my broker, so 1 lot= 13142$ of Dax. Let's calculate yours.

0.31 lot = 0.31 x 13142$ = 4074,02$ . Then calculate your margin requirement. Margin requirement of 1:30 leverage is 3,33% (100/30 , for example, for 1:25 leverage, margin requirement is 100/25=4%), that means you need 3,33% of 4074,02$ to open 0.31 lot position. 3,33% of 4074,02 = 0,033 x 4074,02 = 134,44$ . So you will use 134,44$ of your 250$ to open this position. And your margin level % will be 250$/134,44$ x 100(%) = 186% (Equity/used margin x 100).

And don't keep positions over the weekend, this is my recommendation.

And to check contract size of any symbol on MT4. Right click on the Dax30 in symbol list, click properties (golden $). Then you'll see contract size in the opened window.

It seems to me that calculations are a huge problem for many traders, because it's easy to make a mistake here and it depends on your preparation for trading (and yes, this is exactly the stage of preparation for work), depends on how safe it will be at all stages and whether you can save your capital if something unplanned happens in the market and you can build a system of work that will constantly bring you good profits.
You can learn this, you just need to practice more often and always follow the statistics. In addition, now there are numerous calculators that can be used for this purpose absolutely free. So you should not miss out on these opportunities!

Divide position size by leverage, convert to account currency and you'll get initial margin. What's the problem?